SSS One Physics Objective Examination Questions

Here are the answers to the first 20 physics objective questions:

1. All quantities in physics are said to be

1. physical quantities
2. natural quantities
3. artificial quantities
4. international quantities

Click to reveal answer

Correct Answer: A. physical quantities

Explanation: In physics, quantities that can be measured are referred to as physical quantities. These include fundamental quantities like length, mass, and time, and derived quantities like velocity, force, and energy.

2. Acceleration is defined as

1. velocity change/time
2. distance / time
3. distance × time
4. displacement × time

Click to reveal answer

Correct Answer: A. velocity change/time

Explanation: Acceleration is the rate of change of velocity. Mathematically, it's defined as the change in velocity divided by the time taken for that change: $a = \frac{\Delta v}{\Delta t}$.

3. The S.I unit of energy is

1. Joules
2. watts
3. newtons
4. hertz

Click to reveal answer

Correct Answer: A. Joules

Explanation: The Joule (J) is the SI unit of energy and work. Watts (W) are units of power, Newtons (N) are units of force, and Hertz (Hz) are units of frequency.

4. What will be the acceleration of a car that travelled from a velocity of 35m/s to 50m/s in 7s

1. 1.24m/s²
2. 2.14m/s²
3. 4.21m/s²
4. 3.41m/s²

Click to reveal answer

Correct Answer: B. 2.14m/s²

Explanation: Acceleration ($a$) is calculated as the change in velocity ($\Delta v$) divided by the time taken ($\Delta t$).
Initial velocity ($u$) = $35 \text{ m/s}$
Final velocity ($v$) = $50 \text{ m/s}$
Time ($t$) = $7 \text{ s}$
$a = \frac{v - u}{t} = \frac{50 \text{ m/s} - 35 \text{ m/s}}{7 \text{ s}} = \frac{15 \text{ m/s}}{7 \text{ s}} \approx 2.1428 \text{ m/s}^2$.
Rounding to two decimal places, the acceleration is $2.14 \text{ m/s}^2$.

5. The internationally agreed system of fundamental units (S.I) for physical measurement are

1. newton, feet and second
2. gramme, meter and second
3. kilogramme, meter and second
4. centimeter, gramme and second

Click to reveal answer

Correct Answer: C. kilogramme, meter and second

Explanation: The fundamental SI units for mass, length, and time are the kilogram (kg), meter (m), and second (s), respectively. These are part of the seven base SI units.

6. The earth’s pull on a body is known as

1. mass
2. length
3. volume
4. weight

Click to reveal answer

Correct Answer: D. weight

Explanation: Weight is the force of gravity acting on an object's mass. It is essentially the earth's gravitational pull on a body. Mass is a measure of the amount of matter in an object, which remains constant regardless of gravity.

7. The two forms of mechanical energy are

1. kinetic energy and heat energy
2. kinetic energy and potential energy
3. kinetic energy and electric energy
4. heat energy and electric energy

Click to reveal answer

Correct Answer: B. kinetic energy and potential energy

Explanation: Mechanical energy is the sum of an object's kinetic energy (energy due to motion) and potential energy (energy due to position or state). Heat and electric energy are other forms of energy but not categorized as mechanical energy.

8. Which of the following is the dimension of pressure

1. MLT^-2
2. ML^-1T^-2
3. MLT²T^-3
4. ML^-3

Click to reveal answer

Correct Answer: B. ML^-1T^-2

Explanation: Pressure is defined as Force per unit Area ($P = \frac{F}{A}$).
The dimension of Force (F) is $\text{MLT}^{-2}$ (Mass $\times$ Length $\times$ Time$^{-2}$).
The dimension of Area (A) is $\text{L}^2$ (Length$^2$).
Therefore, the dimension of Pressure is $\frac{\text{MLT}^{-2}}{\text{L}^2} = \text{ML}^{1-2}\text{T}^{-2} = \text{ML}^{-1}\text{T}^{-2}$.

9. 1g is equivalent to

1. 0.001kg
2. 1000kg
3. 0.1kg
4. 100kg

Click to reveal answer

Correct Answer: A. 0.001kg

Explanation: The prefix 'kilo' means 1000. So, 1 kilogram (kg) is equal to 1000 grams (g). To convert grams to kilograms, you divide by 1000.
$1 \text{ g} = \frac{1}{1000} \text{ kg} = 0.001 \text{ kg}$.

10. When the rate of change of a displacement of a body is constant, the body is said to attain

1. average speed
2. uniform, velocity
3. actual velocity
4. instantaneous speed

Click to reveal answer

Correct Answer: B. uniform velocity

Explanation: The rate of change of displacement is defined as velocity. If this rate is constant, it means both the magnitude (speed) and direction of the velocity are unchanging. This condition is known as uniform velocity.

11. Which of the following is a derived unit?

1. kilogramme
2. meter
3. newton
4. kelvin

Click to reveal answer

Correct Answer: C. newton

Explanation: A derived unit is a unit that is formed by combining base SI units. The Newton (N) is a derived unit of force, defined as $\text{kg} \cdot \text{m/s}^2$. Kilogram, meter, and Kelvin are all base SI units for mass, length, and thermodynamic temperature, respectively.

12. The most natural time unit is

1. planet
2. earth
3. equator
4. solar day

Click to reveal answer

Correct Answer: D. solar day

Explanation: The solar day is the most natural unit of time, defined by the Earth's rotation relative to the Sun. It corresponds to one complete rotation of the Earth on its axis concerning the Sun, which determines the cycle of day and night.

13. 1 horse power (1 h.p) is equivalent to

1. 476 watts
2. 647 watts
3. 746 watts
4. 857 watts

Click to reveal answer

Correct Answer: C. 746 watts

Explanation: The conversion factor for horsepower (mechanical horsepower) to watts is approximately 746 watts. This is a standard conversion value used in physics and engineering.

14. Convert 3/4 hours 1/6 minutes 14seconds to seconds

1. 2274s
2. 2427s
3. 2724s
4. 4722s

Click to reveal answer

Correct Answer: A. 2724s

Explanation:
Convert hours to seconds: $3/4 \text{ hours} = 0.75 \text{ hours} \times 3600 \text{ seconds/hour} = 2700 \text{ seconds}$.
Convert minutes to seconds: $1/6 \text{ minutes} = (1/6) \times 60 \text{ seconds/minute} = 10 \text{ seconds}$.
Add the given seconds: $14 \text{ seconds}$.
Total seconds = $2700 \text{ s} + 10 \text{ s} + 14 \text{ s} = 2724 \text{ s}$.

15. Calculate the work done when a force of 7.5newton displace an object through 10meters

1. 75 Joules
2. 50 Joules
3. 57 Joules
4. 65 Joules

Click to reveal answer

Correct Answer: A. 75 Joules

Explanation: Work done ($W$) is calculated as Force ($F$) multiplied by displacement ($d$) in the direction of the force.
$W = F \times d$
$F = 7.5 \text{ N}$
$d = 10 \text{ m}$
$W = 7.5 \text{ N} \times 10 \text{ m} = 75 \text{ J}$.

16. 1 kilowatt of power is equivalent to

1. 100 watts
2. 1000 watts
3. 10000 watts
4. 10 watts

Click to reveal answer

Correct Answer: B. 1000 watts

Explanation: The prefix 'kilo-' in the International System of Units (SI) represents a factor of $10^3$, or 1000. Therefore, 1 kilowatt (kW) is equal to 1000 watts (W).

17. The unit of time falls in the same group of fundamental quantities as

1. mass and density
2. length and volume
3. mass and length
4. density and volume

Click to reveal answer

Correct Answer: C. mass and length

Explanation: In the SI system, time, mass, and length are all fundamental quantities. Density and volume are derived quantities. Density is mass per unit volume, and volume is length cubed.

18. Velocity is defined as

1. distance / time
2. area covered / time
3. distance × time
4. displacement / time

Click to reveal answer

Correct Answer: D. displacement / time

Explanation: Velocity is defined as the rate of change of displacement. It is a vector quantity, meaning it has both magnitude (speed) and direction. Distance/time defines speed, which is a scalar quantity.

19. How many seconds are in one day

1. 68400s
2. 48600s
3. 64800s
4. 86400s

Click to reveal answer

Correct Answer: D. 86400s

Explanation: To find the number of seconds in one day, multiply the number of hours in a day by the number of minutes in an hour, and then by the number of seconds in a minute:
1 day = 24 hours
1 hour = 60 minutes
1 minute = 60 seconds
Seconds in one day = $24 \text{ hours} \times 60 \text{ minutes/hour} \times 60 \text{ seconds/minute} = 86400 \text{ s}$.

20. Convert 36km/hr to m/s

1. 4m/s
2. 9m/s
3. 13m/s
4. 10m/s

Click to reveal answer

Correct Answer: D. 10m/s

Explanation: To convert kilometers per hour (km/hr) to meters per second (m/s), we use the conversion factors:
$1 \text{ km} = 1000 \text{ m}$
$1 \text{ hour} = 3600 \text{ seconds}$
So, $36 \text{ km/hr} = 36 \times \frac{1000 \text{ m}}{3600 \text{ s}} = 36 \times \frac{1}{3.6} \text{ m/s} = 10 \text{ m/s}$.

21. If today is Sunday, what day of the week will it be after 211 days?

1. Monday
2. Tuesday
3. Wednesday
4. Thursday

Click to reveal answer

Correct Answer: A. Monday

Explanation: There are 7 days in a week. To find the day of the week after 211 days, we need to find the remainder when 211 is divided by 7.
$211 \div 7 = 30$ with a remainder of $1$.
This means after 30 full weeks (210 days), it will be Sunday again. One day after that (the 211th day) will be Monday.

22. A geometric figure defined by two reference frames is known as

1. bearing
2. plane
3. pace
4. coordinate

Click to reveal answer

Correct Answer: D. coordinate

Explanation: In geometry and physics, a coordinate system uses one or more numbers (coordinates) to uniquely determine the position of a point or other geometric element. When using two reference frames (e.g., x and y axes), you are defining the position using coordinates.

23. Which of the following is a vector quantity?

1. speed
2. time
3. velocity
4. distance

Click to reveal answer

Correct Answer: C. velocity

Explanation: A vector quantity has both magnitude and direction. Velocity fits this definition (e.g., 10 m/s East). Speed, time, and distance are scalar quantities, meaning they only have magnitude.

24. Given the point A(4,3) and B(1,6), what is the distance AB

1. 2.44m
2. 2.12m
3. 1.22m
4. 4.24m

Click to reveal answer

Correct Answer: D. 4.24m

Explanation: To find the distance between two points $(x_1, y_1)$ and $(x_2, y_2)$, use the distance formula: $D = \sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2}$.
Given A(4,3) and B(1,6):
$D = \sqrt{(1 - 4)^2 + (6 - 3)^2}$
$D = \sqrt{(-3)^2 + (3)^2}$
$D = \sqrt{9 + 9}$
$D = \sqrt{18}$
$D \approx 4.2426 \text{ m}$.
Rounding to two decimal places, the distance is $4.24 \text{ m}$.

25. Which of these is not a method of reducing friction?

1. streamlining
2. lubrication
3. polishing
4. electroplating

Click to reveal answer

Correct Answer: D. electroplating

Explanation: - Streamlining reduces fluid friction (air or water resistance). - Lubrication (e.g., using oil or grease) reduces friction between surfaces by providing a smooth layer. - Polishing makes surfaces smoother, reducing irregularities that cause friction. - Electroplating is a process of coating a metal object with a thin layer of another metal using an electric current, primarily for corrosion resistance or appearance, not directly for reducing friction (though some coatings might incidentally affect friction).

26. A student walks a distance of 3km in 20 minutes. Calculate his average speed leaving your answer in m/s

1. 5m/s
2. 2m/s
3. 2.5m/s
4. 3m/s

Click to reveal answer

Correct Answer: C. 2.5m/s

Explanation: Average speed is calculated as total distance divided by total time.
Distance = $3 \text{ km} = 3 \times 1000 \text{ m} = 3000 \text{ m}$.
Time = $20 \text{ minutes} = 20 \times 60 \text{ seconds} = 1200 \text{ seconds}$.
Average speed = $\frac{\text{Distance}}{\text{Time}} = \frac{3000 \text{ m}}{1200 \text{ s}} = 2.5 \text{ m/s}$.

27. Convert 72km/hr to m/min

1. 120m/min
2. 1200m/min
3. 12m/min
4. 12000m/min

Click to reveal answer

Correct Answer: B. 1200m/min

Explanation: To convert kilometers per hour to meters per minute:
$72 \text{ km/hr} = 72 \times \frac{1000 \text{ m}}{1 \text{ km}} \times \frac{1 \text{ hour}}{60 \text{ minutes}}$
$ = \frac{72 \times 1000}{60} \text{ m/min}$
$ = \frac{72000}{60} \text{ m/min}$
$ = 1200 \text{ m/min}$.

28. Which of the following is not a fundamental unit?

1. radian
2. meter
3. ampere
4. kelvin

Click to reveal answer

Correct Answer: A. radian

Explanation: The radian is a supplementary SI unit for plane angle, not one of the seven base (fundamental) SI units. The seven base SI units are: meter (length), kilogram (mass), second (time), ampere (electric current), kelvin (thermodynamic temperature), mole (amount of substance), and candela (luminous intensity).

Use the information below to answer question 29 and 30.
An object of mass 5kg moves in a circle of radius 10m at uniform speed of 35m/s

29. Calculate the angular velocity

1. 3.5 rad/s
2. 4 rad/s
3. 2 rad/s
4. 8 rad/s

Click to reveal answer

Correct Answer: A. 3.5 rad/s

Explanation: The relationship between linear speed ($v$), angular velocity ($\omega$), and radius ($r$) in circular motion is $v = r\omega$.
Given: $v = 35 \text{ m/s}$, $r = 10 \text{ m}$.
Rearrange the formula to find angular velocity: $\omega = \frac{v}{r}$.
$\omega = \frac{35 \text{ m/s}}{10 \text{ m}} = 3.5 \text{ rad/s}$.

30. What will be the centripetal force?

1. 512N
2. 612.5N
3. 128.5N
4. 471.3N

Click to reveal answer

Correct Answer: B. 612.5N

Explanation: Centripetal force ($F_c$) is given by the formula $F_c = \frac{mv^2}{r}$.
Given: mass ($m$) = $5 \text{ kg}$, velocity ($v$) = $35 \text{ m/s}$, radius ($r$) = $10 \text{ m}$.
$F_c = \frac{5 \text{ kg} \times (35 \text{ m/s})^2}{10 \text{ m}}$
$F_c = \frac{5 \times 1225}{10} \text{ N}$
$F_c = \frac{6125}{10} \text{ N}$
$F_c = 612.5 \text{ N}$.

31. What is the equivalent of a temperature of 120°F in degree Celsius (°C)?

1. 248.00°C
2. 393.00°C
3. 153.00°C
4. 48.90°C

Click to reveal answer

Correct Answer: D. 48.90°C

Explanation: To convert temperature from Fahrenheit (°F) to Celsius (°C), use the formula: $C = \frac{5}{9} (F - 32)$.
Given $F = 120^\circ\text{F}$
$C = \frac{5}{9} (120 - 32)$
$C = \frac{5}{9} (88)$
$C = \frac{440}{9} \approx 48.888...^\circ\text{C}$.
Rounding to two decimal places, the temperature is $48.90^\circ\text{C}$.

32. All these are characteristics of solid state of matter except

1. They have definite shape
2. They have definite volume
3. They have no definite shape and volume
4. They are tightly packed

Click to reveal answer

Correct Answer: C. They have no definite shape and volume

Explanation: Solids are characterized by having a definite shape and a definite volume because their particles are tightly packed in fixed positions. The statement "They have no definite shape and volume" describes gases, not solids.

33. Distance is to speed as displacement is to

1. Acceleration
2. Velocity
3. Position
4. distance

Click to reveal answer

Correct Answer: B. Velocity

Explanation: This question tests the relationship between scalar and vector quantities. - Distance is a scalar quantity, and its rate of change is speed (a scalar). - Displacement is a vector quantity, and its rate of change is velocity (a vector).

34. A thermos flask is used in keeping the temperature of its content constant. This means it prevents heat lost by:
(i) Induction (ii) Conduction (iii) Convection (iv) Radiation (v) Insulation

1. ii, iii and iv
2. i, ii and iv
3. i, ii and v
4. i, iv and v

Click to reveal answer

Correct Answer: A. ii, iii and iv

Explanation: A thermos flask is designed to minimize heat transfer through all three primary modes: - Conduction (ii): The vacuum between the double walls prevents heat transfer by conduction through air. The stopper also prevents conduction. - Convection (iii): The vacuum also prevents heat transfer by convection currents. - Radiation (iv): The silvered surfaces (mirror-like coating) reflect radiant heat, preventing it from entering or leaving the flask. - Induction is not a mode of heat transfer. Insulation (v) is a general term for preventing heat transfer, but conduction, convection, and radiation are the specific mechanisms addressed by the flask's design.

35. Non-conductors are characterized by

1. Low conductivity and high resistivity
2. High conductivity and low resistivity
3. High conductivity and high resistivity
4. Low conductivity and low resistivity

Click to reveal answer

Correct Answer: A. Low conductivity and high resistivity

Explanation: Non-conductors (insulators) are materials that do not allow electric current or heat to flow easily. This property is described by low electrical/thermal conductivity and consequently, high resistivity (resistance to flow).

36. Which of the following is not a factor affecting radiant energy?

1. Quantity of radiation
2. Temperature
3. Surface area
4. Nature of the surface

Click to reveal answer

Correct Answer: A. Quantity of radiation

Explanation: The factors affecting the rate of radiant energy (heat radiation) from a body are: - Temperature: Higher temperature leads to more radiation (Stefan-Boltzmann Law). - Surface area: Larger surface area means more area for radiation. - Nature of the surface: Dull, black surfaces are better emitters/absorbers than shiny, white surfaces (emissivity). "Quantity of radiation" is a consequence or measure of radiation, not a *factor* that determines its rate.

37. The S.I unit of electric charge is

1. Newton
2. Joules
3. Watts
4. Coulomb

Click to reveal answer

Correct Answer: D. Coulomb

Explanation: The Coulomb (C) is the SI unit of electric charge. Newtons (N) are for force, Joules (J) for energy/work, and Watts (W) for power.

38. Which of the following is not an effect of heat on a body?

1. Expansivity
2. Change of state
3. Decrease in temperature
4. Thermionic emission

Click to reveal answer

Correct Answer: C. Decrease in temperature

Explanation: When heat is added to a body, it typically causes: - Expansivity: The body expands (increases in size). - Change of state: It can melt, vaporize, etc. - Increase in temperature: The internal energy increases, leading to a higher temperature (unless it's undergoing a phase change). - Thermionic emission: In some materials (like metals at high temperatures), electrons can be emitted from the surface due to thermal energy. A decrease in temperature happens when heat is *removed* from a body, not when heat is applied to it.

39. The study of charges at rest is known as

1. Electrophorus
2. Electrostatics
3. Electroplating
4. Electroscope

Click to reveal answer

Correct Answer: B. Electrostatics

Explanation: Electrostatics is the branch of physics that deals with electric charges at rest and the forces and fields associated with them. Electrophorus and electroscope are devices, and electroplating is a process involving electric current.

40. A glass rod rubbed with silk produces

1. Positive charge
2. Negative charge
3. Neutral charge
4. None of the above

Click to reveal answer

Correct Answer: A. Positive charge

Explanation: When a glass rod is rubbed with silk, electrons are transferred from the glass to the silk. As a result, the glass rod loses electrons and becomes positively charged, while the silk gains electrons and becomes negatively charged. This is a classic example in electrostatics.

41. A region or space under the action or influence of some physical agencies is known as

1. Force
2. Field
3. Motion
4. Plane

Click to reveal answer

Correct Answer: B. Field

Explanation: In physics, a field is a physical quantity that has a value for each point in space and time. Examples include electric fields, magnetic fields, and gravitational fields, where a force or influence is exerted on objects within that region without direct contact.

42. The temperature of a body increase from 30°C to 70°C, what is the temperature change of the body in Kelvin (K)?

1. 133K
2. 313K
3. 40K
4. 586K

Click to reveal answer

Correct Answer: C. 40K

Explanation: A change in temperature of 1 degree Celsius ($\Delta C$) is equal to a change in temperature of 1 Kelvin ($\Delta K$).
Temperature change in Celsius = Final temperature - Initial temperature
$\Delta C = 70^\circ\text{C} - 30^\circ\text{C} = 40^\circ\text{C}$.
Therefore, the temperature change in Kelvin is also 40 K.
(Note: While converting absolute temperatures, you add 273.15, but for *temperature differences* or *changes*, the magnitude is the same for Celsius and Kelvin scales.)

43. A rod of initial length 2m at a temperature of 25°C is heated to 80°C. Calculate the increase in length of the rod if its linear expansivity $\alpha$ is $4.0 \times 10^{-3} \text{ K}^{-1}$

1. 4.40m
2. 44.00m
3. 0.04m
4. 0.44m

Click to reveal answer

Correct Answer: D. 0.44m

Explanation: The increase in length ($\Delta L$) due to thermal expansion is given by the formula: $\Delta L = L_0 \alpha \Delta T$.
Initial length ($L_0$) = $2 \text{ m}$
Linear expansivity ($\alpha$) = $4.0 \times 10^{-3} \text{ K}^{-1}$
Temperature change ($\Delta T$) = Final temperature - Initial temperature
$\Delta T = 80^\circ\text{C} - 25^\circ\text{C} = 55^\circ\text{C} = 55 \text{ K}$ (since change in °C equals change in K).
$\Delta L = (2 \text{ m}) \times (4.0 \times 10^{-3} \text{ K}^{-1}) \times (55 \text{ K})$
$\Delta L = 2 \times 4.0 \times 55 \times 10^{-3} \text{ m}$
$\Delta L = 8 \times 55 \times 10^{-3} \text{ m}$
$\Delta L = 440 \times 10^{-3} \text{ m}$
$\Delta L = 0.440 \text{ m}$.

44. Negative charge is produced when you rub

1. Glass rod with silk
2. Ebonite rod with silk
3. Ebonite rod with fur
4. Glass rod with fur

Click to reveal answer

Correct Answer: C. Ebonite rod with fur

Explanation: When an ebonite rod is rubbed with fur, electrons are transferred from the fur to the ebonite rod. This causes the ebonite rod to gain electrons and become negatively charged, while the fur becomes positively charged. (Conversely, glass rubbed with silk becomes positively charged.)

45. Very small current can be detected and measured by a sensitive instrument called

1. Ammeter
2. Galvanometer
3. Voltmeter
4. Milliammeter

Click to reveal answer

Correct Answer: B. Galvanometer

Explanation: A galvanometer is a sensitive instrument used for detecting and measuring small electric currents. While an ammeter measures larger currents and a milliammeter measures currents in milliamperes, the galvanometer is specifically known for its sensitivity to very small currents.

46. The rate of flow of electric charges along a conductor is known as

1. Electric current
2. Resistivity
3. Electrostatic
4. Electrolysis

Click to reveal answer

Correct Answer: A. Electric current

Explanation: Electric current is defined as the rate of flow of electric charge. It is typically measured in Amperes (A).

47. A device for converting chemical energy into electric energy is known as

1. Generator
2. Transformer
3. Cell
4. Electric motor

Click to reveal answer

Correct Answer: C. Cell

Explanation: An electric cell (or battery, which is a collection of cells) converts stored chemical energy into electrical energy through chemical reactions. - A generator converts mechanical energy to electrical energy. - A transformer changes AC voltage levels. - An electric motor converts electrical energy to mechanical energy.

48. The most abundant sources of energy is

1. Heat energy
2. Wind energy
3. Solar energy
4. Chemical energy

Click to reveal answer

Correct Answer: C. Solar energy

Explanation: The Sun (solar energy) is by far the most abundant source of energy available on Earth. It powers most natural processes and is the ultimate source for many other forms of energy (like wind, biomass, hydropower). While other forms exist, solar energy's sheer scale and continuous supply make it the most abundant.

49. Which of the following is not an insulator

1. Plastic
2. Paper
3. Wool
4. Metal

Click to reveal answer

Correct Answer: D. Metal

Explanation: Metals are generally excellent electrical and thermal conductors due to their free electrons. Plastic, paper, and wool are all commonly used as electrical insulators, meaning they resist the flow of electricity.

50. Which of the following is not a type of circuit?

1. Close circuit
2. Open circuit
3. Long circuit
4. Short circuit

Click to reveal answer

Correct Answer: C. Long circuit

Explanation: - A closed circuit is a complete path that allows current to flow. - An open circuit has a break in the path, preventing current flow. - A short circuit is an unintended, low-resistance connection that allows current to bypass part of the circuit, often leading to high current and potential damage. - "Long circuit" is not a standard classification or type of electrical circuit in physics.

Use the information below to answer questions 51-52.
If two resistors $7\Omega$ and $8\Omega$ are connected together, calculate their net resistance

51. In series

1. $7\Omega$
2. $15\Omega$
3. $8\Omega$
4. $1\Omega$

Click to reveal answer

Correct Answer: B. $15\Omega$

Explanation: When resistors are connected in series, their total (net) resistance ($R_{total}$) is the sum of individual resistances. $R_{total} = R_1 + R_2$ $R_{total} = 7\Omega + 8\Omega = 15\Omega$.

52. In parallel

1. $3.70\Omega$
2. $7.30\Omega$
3. $1.90\Omega$
4. $6.50\Omega$

Click to reveal answer

Correct Answer: A. $3.70\Omega$

Explanation: When resistors are connected in parallel, the reciprocal of their total (net) resistance ($R_{total}$) is the sum of the reciprocals of individual resistances. $\frac{1}{R_{total}} = \frac{1}{R_1} + \frac{1}{R_2}$ $\frac{1}{R_{total}} = \frac{1}{7\Omega} + \frac{1}{8\Omega}$ $\frac{1}{R_{total}} = \frac{8 + 7}{56} = \frac{15}{56}$ $R_{total} = \frac{56}{15} \approx 3.733\Omega$. Rounding to two decimal places, the resistance is $3.70\Omega$.

53. If an object has mass of 10kg, the weight of the object will be

1. 10N
2. 1N
3. 20N
4. 100N

Click to reveal answer

Correct Answer: D. 100N

Explanation: Weight ($W$) is the force of gravity acting on an object's mass ($m$). It is calculated using the formula $W = mg$, where $g$ is the acceleration due to gravity (approximately $9.8 \text{ m/s}^2$ or $10 \text{ m/s}^2$ for simpler calculations). Given mass ($m$) = $10 \text{ kg}$. Using $g \approx 10 \text{ m/s}^2$ (a common approximation in multiple-choice physics problems unless specified otherwise): $W = 10 \text{ kg} \times 10 \text{ m/s}^2 = 100 \text{ N}$.

54. A resistor with fixed resistance value is known as

1. Variable resistor
2. Normal resistor
3. Complete resistor
4. Standard resistor

Click to reveal answer

Correct Answer: D. Standard resistor

Explanation: A resistor whose resistance value cannot be changed is commonly referred to as a fixed resistor or a standard resistor. A variable resistor (like a rheostat or potentiometer) allows its resistance to be changed.

55. The magnetism of a magnet is stronger at the

1. Pole
2. Bar
3. Field
4. Material

Click to reveal answer

Correct Answer: A. Pole

Explanation: The magnetic force exerted by a magnet is strongest at its poles (north and south poles). This is where the magnetic field lines are most concentrated.

56. The mass of any atom is concentrated at the

1. Proton
2. Nucleus
3. Neutron
4. Electron

Click to reveal answer

Correct Answer: B. Nucleus

Explanation: The nucleus of an atom contains protons and neutrons, which are significantly more massive than electrons. Therefore, almost all of the mass of an atom is concentrated in its nucleus.

57. A thin aluminum plate has a surface of $1.500 \text{m}^2$ at $20^\circ\text{C}$. What will be its surface area when it is cooled to $-20^\circ\text{C}$ (take the linear expansivity of aluminum to be $1.5 \times 10^{-5} \text{ K}^{-1}$)

1. $4.197 \text{m}^2$
2. $9.741 \text{m}^2$
3. $1.4982 \text{m}^2$
4. $7.419 \text{m}^2$

Click to reveal answer

Correct Answer: C. $1.4982 \text{m}^2$

Use the information below to answer questions 58 – 60
A metal rod of length 40.00cm at $20^\circ\text{C}$ is heated to a temperature of $45^\circ\text{C}$. If the new length of the rod is 40.05cm, calculate

58. Its linear expansivity $\alpha$

1. $2.5 \times 10^{-5}\text{K}^{-1}$
2. $5.2 \times 10^{-4}\text{K}^{-1}$
3. $5.0 \times 10^{-4}\text{K}^{-1}$
4. $5.0 \times 10^{-5}\text{K}^{-1}$

Click to reveal answer

Correct Answer: D. $5.0 \times 10^{-5}\text{K}^{-1}$

59. Its area expansivity $\beta$

1. $10.0 \times 10^{-5}\text{K}^{-1}$
2. $5.0 \times 10^{-5}\text{K}^{-1}$
3. $10.4 \times 10^{-4}\text{K}^{-1}$
4. $25.0 \times 10^{-4}\text{K}^{-1}$

Click to reveal answer

Correct Answer: A. $10.0 \times 10^{-5}\text{K}^{-1}$

Explanation: The area expansivity ($\beta$) is approximately twice the linear expansivity ($\alpha$). From Q58, we found $\alpha = 5.0 \times 10^{-5} \text{ K}^{-1}$. $\beta = 2\alpha = 2 \times (5.0 \times 10^{-5} \text{ K}^{-1})$ $\beta = 10.0 \times 10^{-5} \text{ K}^{-1}$.

60. Its volume expansivity $\gamma$

1. $7.5 \times 10^{-5}\text{K}^{-1}$
2. $15.0 \times 10^{-5}\text{K}^{-1}$
3. $15.6 \times 10^{-4}\text{K}^{-1}$
4. $15.0 \times 10^{-4}\text{K}^{-1}$

Click to reveal answer

Correct Answer: B. $15.0 \times 10^{-5}\text{K}^{-1}$

Explanation: The volume expansivity ($\gamma$) is approximately thrice the linear expansivity ($\alpha$). From Q58, we found $\alpha = 5.0 \times 10^{-5} \text{ K}^{-1}$. $\gamma = 3\alpha = 3 \times (5.0 \times 10^{-5} \text{ K}^{-1})$ $\gamma = 15.0 \times 10^{-5} \text{ K}^{-1}$.

61. A piece of solid matter in which the atoms, molecules or ions are arranged in a highly regular repeating pattern or lattice is known as

1. Crystal
2. Unit
3. Cell
4. Amorphous

Click to reveal answer

Correct Answer: A. Crystal

Explanation: A crystal (or crystalline solid) is a solid material whose constituent atoms, molecules, or ions are arranged in an ordered pattern extending in all three spatial dimensions. Amorphous solids, on the other hand, lack this long-range order.

62. The deformation of a material is said to be elastic if the material

1. Continues to stretch
2. Return to its original position
3. Cannot stretch
4. Breaks into two parts

Click to reveal answer

Correct Answer: B. Return to its original position

Explanation: An elastic deformation is one where the material returns to its original shape and size once the applied deforming force is removed. If it does not return completely, the deformation is plastic.

63. Which of the following is not an example of face-centred cubic crystal

1. Copper
2. Silver
3. Chromium
4. Lead

Click to reveal answer

Correct Answer: C. Chromium

Explanation: Face-centered cubic (FCC) is a common crystal structure. Copper, silver, and lead are well-known examples of metals that crystallize in an FCC structure. Chromium, however, typically crystallizes in a body-centered cubic (BCC) structure.

64. Error due to parallax can be avoided on all the following apparatus except

1. Potentiometer
2. Galvanometer
3. Stop clock
4. Pendulum bob

Click to reveal answer

Correct Answer: D. Pendulum bob

Explanation: Parallax error occurs when the observer's eye is not in line with the scale and the pointer, leading to an incorrect reading. Instruments with scales and pointers, such as a potentiometer, galvanometer, and stop clock (analog ones), are susceptible to parallax error. A pendulum bob is a simple mass on a string; its motion is observed, but there isn't a scale or pointer on the bob itself where parallax would directly affect a measurement of its position or time (though timing its swing with a stop clock might involve parallax in reading the clock). The bob itself doesn't have a reading scale.

65. The ability of material to regain its original shape and size after being distorted by an external force is known as

1. Deformation
2. Plasticity
3. Extension
4. Elasticity

Click to reveal answer

Correct Answer: D. Elasticity

Explanation: Elasticity is the physical property of materials that describes their ability to return to their original shape and size after the removal of external deforming forces. Deformation is the act of changing shape, plasticity is the opposite of elasticity (retains deformation), and extension is a type of deformation.

66. Non-crystalline substances are said to be amorphous because

1. they are tightly packed
2. They have definite shape
3. They are without form
4. They are usually soluble

Click to reveal answer

Correct Answer: C. They are without form

Explanation: The word "amorphous" comes from Greek, meaning "without form" (a- "not, without" + morphē "form, shape"). Amorphous substances lack the ordered, repeating crystalline structure. While they may appear to have a definite shape (like a piece of glass), their internal atomic arrangement is disordered.

67. One similarity between viscosity and friction is that both forces

1. Depend on areas of surface in contact
2. Oppose relative motion between surfaces
3. Depend on normal reaction
4. Depend on relative motion between two layers

Click to reveal answer

Correct Answer: B. Oppose relative motion between surfaces

Explanation: Both viscosity (internal friction in fluids) and friction (between solid surfaces) are dissipative forces that oppose relative motion. - Viscosity opposes the relative motion between layers of a fluid. - Friction opposes the relative motion between two solid surfaces in contact. While some forms might depend on area (viscosity) or normal reaction (friction), their fundamental similarity lies in opposing motion.

68. A force of 1.8N extends a wire by 0.4cm, what force will extend the wire by 1.25cm if the elastic limit is not exceeded?

1. 5.625N
2. 65.205N
3. 25.562N
4. 2.565N

Click to reveal answer

Correct Answer: A. 5.625N

Explanation: This problem can be solved using Hooke's Law, which states that the force ($F$) required to extend or compress a spring (or wire) is directly proportional to the distance of that extension or compression ($x$), provided the elastic limit is not exceeded. Mathematically, $F = kx$, where $k$ is the spring constant (or force constant). First, find the spring constant ($k$) using the initial information: $F_1 = 1.8 \text{ N}$ $x_1 = 0.4 \text{ cm} = 0.004 \text{ m}$ (convert cm to m for SI units, though keeping units consistent will also work if using ratios). $k = \frac{F_1}{x_1} = \frac{1.8 \text{ N}}{0.4 \text{ cm}} = 4.5 \text{ N/cm}$. Now, use this constant to find the force required for the new extension: $x_2 = 1.25 \text{ cm}$ $F_2 = k \times x_2 = 4.5 \text{ N/cm} \times 1.25 \text{ cm}$ $F_2 = 5.625 \text{ N}$.

69. The energy contained in a wire when it is extended by 0.02m by a force of 500N is

1. 5J
2. 10J
3. 103J
4. 104J

Click to reveal answer

Correct Answer: A. 5J

Explanation: The energy stored in an extended or compressed elastic material is called elastic potential energy ($U$). For a material obeying Hooke's Law, this energy can be calculated by the formula $U = \frac{1}{2}Fx$, where $F$ is the applied force and $x$ is the extension. (This formula assumes the force increases linearly from 0 to F). Given: Force ($F$) = $500 \text{ N}$ Extension ($x$) = $0.02 \text{ m}$ $U = \frac{1}{2} \times 500 \text{ N} \times 0.02 \text{ m}$ $U = 250 \times 0.02 \text{ J}$ $U = 5 \text{ J}$.

70. The ability of a stretched or compressed elastic material to do work is called

1. Elastic potential energy
2. Force constant
3. Stiffness of material
4. Workdone

Click to reveal answer

Correct Answer: A. Elastic potential energy

Explanation: The energy stored in a stretched or compressed elastic material due to its deformation is called elastic potential energy. This stored energy can then be converted into other forms of energy (like kinetic energy) as the material returns to its original shape, thus doing work. For example, a stretched spring or a bent bow stores elastic potential energy.

71. A component specifically designed to provide a known amount of resistance in a circuit is known as

1. Capacitor
2. Resistor
3. Inductor
4. Diode

Click to reveal answer

Correct Answer: B. Resistor

Explanation: A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element. Its primary function is to oppose the flow of electric current, thereby providing a known amount of resistance. - A capacitor stores electrical energy in an electric field. - An inductor stores energy in a magnetic field. - A diode allows current to flow in one direction only.

72. The ratio of stress to strain in an elastic material is known as

1. Hooke’s law
2. Young’s modulus
3. Elastic constant
4. Elastic potential energy

Click to reveal answer

Correct Answer: B. Young’s modulus

Explanation: For an elastic material under tensile or compressive stress, the ratio of stress (force per unit area) to strain (fractional change in length) is a constant known as Young's Modulus (or Modulus of Elasticity). It's a measure of the stiffness of an elastic material. While Hooke's Law describes the linear relationship between force and extension, Young's Modulus is a material property that quantifies this relationship in terms of stress and strain.

73. A spiral spring is compressed by 0.03m. Calculate the energy stored in the spring if its force constant is 300N

1. 13.500J
2. 1.305J
3. 0.135J
4. 531.000J

Click to reveal answer

Correct Answer: C. 0.135J

Explanation: The energy stored in a spring (elastic potential energy, $U$) is given by the formula $U = \frac{1}{2}kx^2$, where $k$ is the force constant (spring constant) and $x$ is the compression or extension. Given: Compression ($x$) = $0.03 \text{ m}$ Force constant ($k$) = $300 \text{ N/m}$ (Assuming N for force, and the unit implies N/m for constant) $U = \frac{1}{2} \times 300 \text{ N/m} \times (0.03 \text{ m})^2$ $U = 150 \times 0.0009 \text{ J}$ $U = 0.135 \text{ J}$.

74. The three types of circuit are the following except

1. Closed circuit
2. Open circuit
3. Loop circuit
4. Short circuit

Click to reveal answer

Correct Answer: C. Loop circuit

Explanation: In basic circuit theory, the common types of circuits are: - Closed circuit: A complete path for current to flow. - Open circuit: A break in the path, preventing current flow. - Short circuit: An unintended low-resistance path that allows current to bypass part of the circuit, usually leading to high current. "Loop circuit" is not a standard classification of circuit types, although a closed circuit does form a loop.

75. The S.I unit of strain is

1. N/m²
2. N/m
3. Nm
4. No unit

Click to reveal answer

Correct Answer: D. No unit

Explanation: Strain is defined as the ratio of change in dimension to the original dimension (e.g., change in length/original length, or change in volume/original volume). Since it is a ratio of two quantities with the same units, the units cancel out. Therefore, strain is a dimensionless quantity and has no S.I. unit. - N/m² is the unit of stress or pressure. - N/m could be a force constant or surface tension. - Nm is the unit of work/energy (Joules) or torque.

76. Which of the following is not a fundamental S.I unit?

1. Kilogram (kg)
2. Meter (m)
3. Second (s)
4. Newton (N)

Click to reveal answer

Correct Answer: D. Newton (N)

Explanation: The fundamental S.I. units (or base units) are the basic units from which all other S.I. units are derived. There are seven fundamental S.I. units: meter (length), kilogram (mass), second (time), ampere (electric current), Kelvin (thermodynamic temperature), mole (amount of substance), and candela (luminous intensity). - Kilogram (kg), Meter (m), and Second (s) are fundamental S.I. units. - Newton (N) is the S.I. unit of force, but it is a derived unit ($1 \text{ N} = 1 \text{ kg} \cdot \text{m/s}^2$).

77. The tendency of a liquid to rise or fall in a narrow tube is known as

1. Adhesion
2. Surface tension
3. Cohesion
4. Capillarity

Click to reveal answer

Correct Answer: D. Capillarity

Explanation: Capillarity (or capillary action) is the ability of a liquid to flow in narrow spaces (like a thin tube or porous material) without the assistance of, or even in opposition to, external forces like gravity. This phenomenon is a result of the intermolecular forces (cohesion and adhesion) between the liquid and the surrounding solid surface. - Adhesion is the attraction between different types of molecules. - Surface tension is the cohesive force among liquid molecules at the surface. - Cohesion is the attraction between like molecules.

78. In graphing, the line that must cut across your best points is known as

1. Straight line
2. Tangential line
3. Line best fit
4. Best graph line

Click to reveal answer

Correct Answer: C. Line best fit

Explanation: A line of best fit (or best-fit line) is a straight line that best represents the data on a scatter plot. It is typically drawn to show the general trend of the data points, aiming to minimize the overall distance between the line and all the data points, rather than necessarily cutting through any specific points.

79. What is the net number of atoms per unit cell in a body-centred cubic (BCC) crystal

1. One
2. Nine
3. Fourteen
4. Eight

Click to reveal answer

Correct Answer: A. One

73. A spiral spring is compressed by 0.03m. Calculate the energy stored in the spring if its force constant is 300N

1. 13.500J
2. 1.305J
3. 0.135J
4. 531.000J

Click to reveal answer

Correct Answer: C. 0.135J

Explanation: The energy stored in a spring (elastic potential energy, $U$) is given by the formula $U = \frac{1}{2}kx^2$, where $k$ is the force constant (spring constant) and $x$ is the compression or extension. Given: Compression ($x$) = $0.03 \text{ m}$ Force constant ($k$) = $300 \text{ N/m}$ $U = \frac{1}{2} \times 300 \text{ N/m} \times (0.03 \text{ m})^2$ $U = 150 \times 0.0009 \text{ J}$ $U = 0.135 \text{ J}$.

74. The three types of circuit are the following except

1. Closed circuit
2. Open circuit
3. Loop circuit
4. Short circuit

Click to reveal answer

Correct Answer: C. Loop circuit

Explanation: In basic circuit theory, the common types of circuits are: - Closed circuit: A complete path for current to flow. - Open circuit: A break in the path, preventing current flow. - Short circuit: An unintended low-resistance path that allows current to bypass part of the circuit, usually leading to high current. "Loop circuit" is not a standard classification of circuit types, although a closed circuit does form a loop.

75. The S.I unit of strain is

1. N/m²
2. N/m
3. Nm
4. No unit

Click to reveal answer

Correct Answer: D. No unit

Explanation: Strain is defined as the ratio of change in dimension to the original dimension (e.g., change in length/original length, or change in volume/original volume). Since it is a ratio of two quantities with the same units, the units cancel out. Therefore, strain is a dimensionless quantity and has no S.I. unit. - N/m² is the unit of stress or pressure. - N/m could be a force constant or surface tension. - Nm is the unit of work/energy (Joules) or torque.

76. Which of the following is not a fundamental S.I unit?

1. Kilogram (kg)
2. Meter (m)
3. Second (s)
4. Newton (N)

Click to reveal answer

Correct Answer: D. Newton (N)

Explanation: The fundamental S.I. units (or base units) are the basic units from which all other S.I. units are derived. There are seven fundamental S.I. units: meter (length), kilogram (mass), second (time), ampere (electric current), Kelvin (thermodynamic temperature), mole (amount of substance), and candela (luminous intensity). - Kilogram (kg), Meter (m), and Second (s) are fundamental S.I. units. - Newton (N) is the S.I. unit of force, but it is a derived unit ($1 \text{ N} = 1 \text{ kg} \cdot \text{m/s}^2$).

77. The tendency of a liquid to rise or fall in a narrow tube is known as

1. Adhesion
2. Surface tension
3. Cohesion
4. Capillarity

Click to reveal answer

Correct Answer: D. Capillarity

Explanation: Capillarity (or capillary action) is the ability of a liquid to flow in narrow spaces (like a thin tube or porous material) without the assistance of, or even in opposition to, external forces like gravity. This phenomenon is a result of the intermolecular forces (cohesion and adhesion) between the liquid and the surrounding solid surface. - Adhesion is the attraction between different types of molecules. - Surface tension is the cohesive force among liquid molecules at the surface. - Cohesion is the attraction between like molecules.

78. In graphing, the line that must cut across your best points is known as

1. Straight line
2. Tangential line
3. Line best fit
4. Best graph line

Click to reveal answer

Correct Answer: C. Line best fit

Explanation: A line of best fit (or best-fit line) is a straight line that best represents the data on a scatter plot. It is typically drawn to show the general trend of the data points, aiming to minimize the overall distance between the line and all the data points, rather than necessarily cutting through any specific points.

79. What is the net number of atoms per unit cell in a body-centred cubic (BCC) crystal

1. One
2. Nine
3. Fourteen
4. Eight

Click to reveal answer

Correct Answer: A. One

80. A spring of force constant 500N/m is compressed such that its length shortens by 5cm. The energy stored in the spring is

1. 0.625J
2. 6.250J
3. 62.500J
4. 625.000J

Click to reveal answer

Correct Answer: A. 0.625J

Explanation: The energy stored in a spring (elastic potential energy, $U$) is given by the formula $U = \frac{1}{2}kx^2$, where $k$ is the force constant and $x$ is the compression or extension. Given: Force constant ($k$) = $500 \text{ N/m}$ Compression ($x$) = $5 \text{ cm} = 0.05 \text{ m}$ (convert cm to m). $U = \frac{1}{2} \times 500 \text{ N/m} \times (0.05 \text{ m})^2$ $U = 250 \times 0.0025 \text{ J}$ $U = 0.625 \text{ J}$.

81. All the following are viscous materials except

1. Engine oil
2. Palm oil
3. Grease
4. Kerosine

Click to reveal answer

Correct Answer: D. Kerosine

Explanation: Viscosity is a measure of a fluid's resistance to flow. Highly viscous liquids are thick and flow slowly. - Engine oil, palm oil, and grease are all examples of relatively viscous liquids. - Kerosine (or kerosene) is a much less viscous liquid; it flows easily and is considered to have low viscosity compared to the others.

82. Coils of wire in a circuit are meant to

1. provide an amount of resistance in the circuit
2. Bias the circuit
3. Limit or slow the rate or amount of charges entering the circuit
4. Convert alternating current to direct current

Click to reveal answer

Correct Answer: C. Limit or slow the rate or amount of charges entering the circuit

Explanation: Coils of wire, when acting as inductors, are specifically designed to limit or slow the rate of change of current (flow of charges) in a circuit. They do this by storing energy in a magnetic field, and opposing changes in current. While all wires have some resistance, and coils can be designed to provide resistance, their primary function as "coils" or inductors is related to their inductive reactance in AC circuits or their ability to oppose current changes in general. - Resistors provide a fixed amount of resistance. - Biasing usually refers to setting operating points for semiconductor devices. - Diodes (or rectifiers) convert AC to DC.

83. The tendon in a man’s leg is 0.01m long. If a force of 5N stretches the tendon by $2.0 \times 10^{-5}$ m, calculate the strain on the muscles

1. $5 \times 10^6$
2. $2 \times 10^{-3}$
3. $5 \times 10^2$
4. $2 \times 10^{-7}$

Click to reveal answer

Correct Answer: B. $2 \times 10^{-3}$

Explanation: Strain is defined as the ratio of the change in length ($\Delta L$) to the original length ($L_0$). Given: Original length ($L_0$) = $0.01 \text{ m}$ Extension ($\Delta L$) = $2.0 \times 10^{-5} \text{ m}$ Strain = $\frac{\Delta L}{L_0} = \frac{2.0 \times 10^{-5} \text{ m}}{0.01 \text{ m}}$ Strain = $\frac{2.0 \times 10^{-5}}{1 \times 10^{-2}}$ Strain = $2.0 \times 10^{-5} \times 10^2 = 2.0 \times 10^{-3}$. Note that strain has no units.

84. The process of checking for faulty electrical components and ensuring continuity on circuit board or panel is known as

1. Troubleshooting
2. Overhauling
3. Maintenance
4. Repairing

Click to reveal answer

Correct Answer: A. Troubleshooting

Explanation: Troubleshooting is the systematic process of finding and fixing problems, especially in electrical or mechanical systems. It specifically involves identifying the cause of a malfunction and then determining a solution. - Overhauling is a complete disassembly, inspection, repair, and reassembly. - Maintenance is routine upkeep to prevent failures. - Repairing is the act of fixing a faulty component or system once identified.

85. When an object falls through a viscous liquid, it is subjected to the following forces except

1. Tension
2. Weight
3. Upthrust
4. Viscous force

Click to reveal answer

Correct Answer: A. Tension

Explanation: When an object falls through a viscous liquid, it experiences: - Weight: The downward force due to gravity. - Upthrust (or buoyant force): The upward force exerted by the fluid, equal to the weight of the fluid displaced. - Viscous force (or drag force): The resistive force exerted by the liquid due to its viscosity, opposing the motion of the object. Tension is a force transmitted through a string, rope, cable, or similar one-dimensional continuous object when it is pulled tight by forces acting from opposite ends. An object falling freely (even through a liquid) is not typically subjected to tension unless it is suspended or attached to something.

86. Which of the following is not a common practical error in physics?

1. Systematic error
2. Physical error
3. Random error
4. Zero error

Click to reveal answer

Correct Answer: B. Physical error

Explanation: In experimental physics, common types of errors are: - Systematic errors: Errors that consistently affect measurements in the same direction (e.g., due to faulty calibration, environmental factors). - Random errors: Errors that vary unpredictably from one measurement to the next (e.g., due to limitations in reading precision, unpredictable fluctuations). - Zero error: A type of systematic error where the measuring instrument does not read zero when it should. "Physical error" is not a standard classification of experimental errors in physics. Errors are generally categorized as systematic or random, and specific types like zero error fall under them.

87. All the following are non-viscous liquid except

1. Water
2. Fuel
3. Glycerine
4. Kerosine

Click to reveal answer

Correct Answer: C. Glycerine

Explanation: A non-viscous liquid flows very easily, meaning it has low viscosity. - Water, fuel (like gasoline), and kerosine are all examples of liquids with relatively low viscosity. - Glycerine (or glycerol) is known for being a highly viscous liquid; it is thick and flows slowly at room temperature, making it the exception among the given choices as it is *not* non-viscous.

Use the information below to answer questions 88-90
A force of 40N applied at the end of a wire of length 4m and radius 0.001m processes an extension of 0.24mm. Take $\pi = 3.142$ and calculate

88. Stress on the wire

1. $6.00 \times 10^{-5} \text{ N/m}^2$
2. $2.12 \times 10^{11} \text{ N/m}^2$
3. $21.20 \times 10^{-7} \text{ N/m}^2$
4. $12.74 \times 10^6 \text{ N/m}^2$

Click to reveal answer

Correct Answer: D. $12.74 \times 10^6 \text{ N/m}^2$

Explanation: Stress ($\sigma$) is defined as force per unit cross-sectional area: $\sigma = \frac{F}{A}$. Given: Force ($F$) = $40 \text{ N}$ Radius ($r$) = $0.001 \text{ m}$ The cross-sectional area ($A$) of the wire (assuming it's circular) is $A = \pi r^2$. $A = 3.142 \times (0.001 \text{ m})^2$ $A = 3.142 \times (1 \times 10^{-3} \text{ m})^2$ $A = 3.142 \times 1 \times 10^{-6} \text{ m}^2 = 3.142 \times 10^{-6} \text{ m}^2$. Now, calculate the stress: $\sigma = \frac{40 \text{ N}}{3.142 \times 10^{-6} \text{ m}^2}$ $\sigma = \frac{40}{3.142} \times 10^6 \text{ N/m}^2$ $\sigma \approx 12.7307 \times 10^6 \text{ N/m}^2$. Rounding to two decimal places, $\sigma \approx 12.73 \times 10^6 \text{ N/m}^2$, which is closest to $12.74 \times 10^6 \text{ N/m}^2$.

89. Strain in the wire

1. $5.0 \times 10^6$
2. $2.0 \times 10^{-3}$
3. $12.0 \times 10^2$
4. $6.0 \times 10^{-5}$

Click to reveal answer

Correct Answer: D. $6.0 \times 10^{-5}$

Explanation: Strain ($\epsilon$) is defined as the ratio of the extension ($\Delta L$) to the original length ($L_0$). Given: Original length ($L_0$) = $4 \text{ m}$ Extension ($\Delta L$) = $0.24 \text{ mm} = 0.24 \times 10^{-3} \text{ m}$ (convert mm to m). $\epsilon = \frac{\Delta L}{L_0} = \frac{0.24 \times 10^{-3} \text{ m}}{4 \text{ m}}$ $\epsilon = \frac{0.24}{4} \times 10^{-3} = 0.06 \times 10^{-3}$ $\epsilon = 6.0 \times 10^{-2} \times 10^{-3} = 6.0 \times 10^{-5}$. Strain is a dimensionless quantity, so it has no unit.

90. Young’s modulus for the material of the wire

1. $2.12 \times 10^{11}\text{N/m}^2$
2. $12.74 \times 10^6\text{N/m}^2$
3. $21.20 \times 10^{-6}\text{N/m}^2$
4. $41.27 \times 10^{11}\text{N/m}^2$

Click to reveal answer

Correct Answer: A. $2.12 \times 10^{11}\text{N/m}^2$

Explanation: Young's Modulus ($Y$) is the ratio of stress ($\sigma$) to strain ($\epsilon$): $Y = \frac{\text{Stress}}{\text{Strain}}$. From Q88, Stress ($\sigma$) $\approx 12.74 \times 10^6 \text{ N/m}^2$. (Using more precise value: $12.7307 \times 10^6 \text{ N/m}^2$) From Q89, Strain ($\epsilon$) = $6.0 \times 10^{-5}$. $Y = \frac{12.7307 \times 10^6 \text{ N/m}^2}{6.0 \times 10^{-5}}$ $Y = \frac{12.7307}{6.0} \times 10^{6 - (-5)} \text{ N/m}^2$ $Y = 2.12178... \times 10^{11} \text{ N/m}^2$. Rounding to two decimal places, $Y \approx 2.12 \times 10^{11} \text{ N/m}^2$.