PHYSICS SET 03

Question No.1

The Physical quantity obtained by the division of linear momentum of a body to its velocity is____

1. Velocity
2. Acceleration
3. Mass
4. Force

Select Answer

Correct Answer: ( C )  

Question No.2

Candela is the unit of_______

1. Luminous flux
2. Luminous effect
3. Luminous intensity
4. None of these

Select Answer

Correct Answer: ( C )  

Question No.3

Force is the product of ______

1. Mass and velocity
2. Mass and acceleration
3. Weight and velocity
4. Weight and acceleration

Select Answer

Correct Answer: ( B )  

Question No.4

The velocity of light in vacuum is ________

1. 9 × 10² m/sec
2. 3 × 10⁸ m/s
3. 3 × 10¹¹ m/s
4. 2 × 10⁶ m/s

Select Answer

Correct Answer: ( B )  

Question No.5

The weight of an object of mass 5 kg can be expressed as________

1. 5 N
2. 9.8N
3. 19 N
4. 49 N

Select Answer

Correct Answer: ( D )  

Question No.6

Lumen is the unit of ______

1. Luminous Intensity
2. Luminous Flux
3. Bothe of these
4. None of these

Select Answer

Correct Answer: ( B )  

Question No.7

The blackboard seems black because it_________

1. Absorbs black colour
2. Reflects every colour
3. Reflects black colour
4. Doesn't reflect any colour

Select Answer

Correct Answer: ( D )  

Question No.8

A cricket player catches a fast moving ball by pulling his hand back because_____

1. The ball can come to a position of rest
2. The ball can be accelerated
3. The ball can exert a larger force
4. The ball can exert a lesser force

Select Answer

Correct Answer: ( C )  

Question No.9

In which of the following kinetic energy doesn't exist?

1. Fired bullet
2. Flowing water
3. Imparted hammer
4. Stretched bow

Select Answer

Correct Answer: ( D )  

Question No.10

If a ship moves from fresh water into seawater, it will_____

1. Sink completely
2. Sink a little bit
3. Rise a little higher
4. Remain unaffected

Select Answer

Correct Answer: ( C )  

Question No.11

The focal length of a convex lens is _____

1. the same for all colours
2. shorter for blue light than for red
3. shorter for red light than for blue
4. maximum for yellow light

Select Answer

Correct Answer: ( B )  

Question No.12

The sudden downfall of the reading of barometer indicates that the weather will be______

1. Stabel and calm
2. Rainy
3. Stormy
4. Cyclonic

Select Answer

Correct Answer: ( C )  

Question No.13

Which of the following force is exerted by a cream separator machine of the milk?

1. Centrifugal force
2. Centripetal force
3. Non-central force
4. External force

Select Answer

Correct Answer: ( A )  

Question No.14

The person sitting in a lift or elevator will experience more when_____

1. the lift is accelerated downwards
2. the lift is accelerated upwards
3. it is coming downwards with equal velocity
4. it is going upwards with equal velocity

Select Answer

Correct Answer: ( B )  

Question No.15

The weight of a human body is _____

1. Same at every places on the earth's surface
2. Maximum at equator
3. Maximum at poles
4. More on mountains than the plains

Select Answer

Correct Answer: ( C )  

Question No.16

If the weight of and object is 960 N on the earth, then his weight on the moon will be____

1. 9600N
2. 160N
3. 96N
4. 60N

Select Answer

Correct Answer: ( B )  

Question No.17

The product of the moment of inertia and the angular acceleration is___________

1. Force
2. Torque
3. Work
4. Angular momentum

Select Answer

Correct Answer: ( B )  

Question No.18

If a moving body doubles its velocity then the kinetic energy of he body will be______

1. Four times
2. Double
3. Three times
4. Remain the same

Select Answer

Correct Answer: ( A )  

Question No.19

The SI unit of the Young's modulus of elasticity is_________

1. dyne/cm
2. newton/meter
3. newton/meter²
4. newton-sec

Select Answer

Correct Answer: ( C )  

Formula used and units

${\displaystyle E={\frac {\sigma }{\varepsilon }}},$ where

• $ E $ is Young's modulus
• $ \sigma $ is the uniaxial stress, or uniaxial force per unit surface
• $ \varepsilon  $ is the strain, or proportional deformation (change in length divided by original length); it is dimensionless. 

 

Both $ E $ and $ \sigma $  have units of pressure, while $\varepsilon $ is dimensionless. Young's moduli are typically so large that they are expressed not in pascals but in megapascals (MPa or N/mm²) or gigapascals (GPa or kN/mm²).

Question No.20

If the weight of an object on the earth's surface is 29.4 N then the mass of the object would be______

1. 2kg
2. 3kg
3. 4kg
4. 29.4kg

Select Answer

Correct Answer: ( B )      

Weight = Mass  × acceleration due to gravity. 

29.4 = Mass ×  9.8 m/s²

 Mass = $ {29.4 N \over 9.8 m/s ^2 }= 3kg $