JEE Questions for Physics Work Energy And Power Quiz 4 - MCQExams.com

A small body is projected in a direction inclined at 45º to the horizontal with kinetic energy K. At the top of its flight, its kinetic energy will be:
  • Zero
  • K/2
  • K/4

  • Physics-Work Energy and Power-97602.png
Two springs have their force constants k1 and k2. These are extended through the same distance x. If their elastic energies are E1 and E2, then E1 : E2 will be :

  • Physics-Work Energy and Power-97604.png
  • 2)
    Physics-Work Energy and Power-97605.png

  • Physics-Work Energy and Power-97606.png

  • Physics-Work Energy and Power-97607.png
A compressor A compresses one litre of air from a pressure of 1atmosphere to a pressure of 3 atmosphere and does work WA . But compressor B compresses one litre of water from a pressure of one atmosphere to three atmosphere and does work WB, then
  • WA = WB
  • WA < WB

  • Physics-Work Energy and Power-97609.png
  • WA > WB
Two solid rubber balls A and B having masses 200 & 400 gm respectively are moving in opposite direction with velocity of A equal to 0.3 m/sec. After collision, the two balls come to rest when the velocity of B is :
  • 0.15 m/sec
  • 1.5 m/sec
  • –0.15 m/sec
  • None of the above
A neutron travelling with a velocity v and K.E ‘E’ collides perfectly elastically head on with nucleus of an atom of mass number A at rest. The fraction of total energy retained by the neutron is :

  • Physics-Work Energy and Power-97612.png
  • 2)
    Physics-Work Energy and Power-97613.png

  • Physics-Work Energy and Power-97614.png

  • Physics-Work Energy and Power-97615.png
A shell initially at rest explodes into two pieces of equal mass, the two pieces will :
  • move with different velocities in different directions
  • move with the same velocity in opposite directions
  • move with the same velocity in the same direction
  • be at rest
If water falls from a dam into a turbine wheel 19.6 m below then velocity of water at turbine, is (Take g = 9.8 m/s2)
  • 9.8 m/s
  • 19.6 m/s
  • 39.2 m/s
  • 98.0 m/s
A bomb of mass 1 kg is thrown vertically upwards with a speed of 100 m/s. After 5 seconds, it explodes into two fragments. One fragment of mass 400 gram is found to go down with a speed of 25 m/s. what will happen to the second fragment just after the explosion? (g = 10 m /s2)
  • it will go upwards with speed 100 m/s
  • it will go upwards with speed 40 m/s
  • it will go upwards with speed 60 m/s
  • it will go downwards with speed 40 m/s
A spring of force constant 800 N/m has an extension of 5 cm. The work done in extending it from 5 cm to 15 cm is
  • 16 J
  • 8 J
  • 32J
  • 24 J
A ball whose K.E. is E is projected at an angle of 450 to the horizontal.The kinetic energy of the ball at the highest point of its flight will be
  • E
  • E / √2
  • E/2
  • zero
The kinetic energy K of a particle moving in a straight line depends on the distance s as K = as2. The force acting on the particle is
  • 2 as
  • 2 m as
  • 2a
  • √as2
A bullet is fired normally on a wooden plank, which is immovable. It loses 25% of its momentum in penetrating a thickness of 3.5 cm the total thickness penetrated by the bullet is
  • 10 cm
  • 8 cm
  • 12 cm
  • 14 cm
A tennis ball falls freely from a height H on to an inclined smooth plane making an angle of 450 with horizontal. After bouncing, the ball falls on the plane again. The distance between the two points where the ball strikes the plane is

  • Physics-Work Energy and Power-97622.png
  • 2)
    Physics-Work Energy and Power-97623.png

  • Physics-Work Energy and Power-97624.png
  • H
The mass of a car is 1000 kg. How much work is required to be done on it to make it move with a speed of 36 km/h ?
  • 2.5 × 104 J
  • 5 × 103 J
  • 500 J
  • 5 × 104 J
A spring gun of spring constant 90 × 102N/M is compressed by a ball of mass 16g. If the trigger is pulled, calculate the velocity of ball
  • 60 m/s
  • 3 m/s
  • 90 m/s
  • 30 m/s
The potential energy of a body is given by U = A – Bx2 (where x is displacement). The magnitude of force acting on the particle is
  • constant
  • proportional to x
  • proportional to x2
  • Inversely proportional to x
A particle is moving under the influence of a force given by F = kx, where k is a constant and x is the distance moved. What energy (in joule) gained by the particle in moving from x = 1m to x = 3m ?
  • 2 k
  • 3 k
  • 4 k
  • 9 k
The decreases in the potential energy of a ball of mass 25 kg which falls from a height of 40 cm is
  • 968 J
  • 100 J
  • 1980 J
  • 200 J
A rope-way trolly of mass 1200kg uniformly from rest to a velocity of 72 km/h in 6s. What is the average power of the engine during this period in watt ?(Neglect friction)
  • 400 W
  • 40,000 W
  • 24000 W
  • 4000 W
If the force F is applied on a body and it moves with a velocity v, the power will be
  • Fv
  • F/v
  • F/v2
  • Fv2
The coefficient of restitution e for a perfectly elastic collision is
  • 1
  • 0
  • ∞
  • –1
Two balls at same temperature collide. What is conserved
  • Temperature
  • velocity
  • kinetic energy
  • momentum
A ball is allowed to fall from a height 20m . If there is 30% loss of energy due to impact, then after one impact ball will go up to
  • 18 m
  • 16 m
  • 12 m
  • 14 m
A ball dropped from a height of 4m rebounds to a height of 2.4m after hitting the ground. Then the percentage of energy lost is
  • 40
  • 50
  • 30
  • 600
If the momentum of a body is increased by 100%, then the percentage increase in the kinetic energy is
  • 150%
  • 200%
  • 225%
  • 300%
Four particles given, have same momentum. Which has maximum kinetic energy
  • Proton
  • Electron
  • Deutron
  • α-particles
A body of mass m1 is moving with a velocity v. It collides with another stationary body of mass m1. They get embeded. At the point of collision, the velocity of the system
  • Increases
  • Decreases but does not become zero
  • Remains same
  • Become zero
Assertion : In the elastic collision between two bodies, the relative speed of the bodies after collision is equal to the relative speed before the collision.
Reason : In the elastic collision the linear momentum of the system is conserved.
  • If both assertion and reason and the reason is the correct explanation of the Assertion.
  • If both assertion and reason are true but reason is not the correct explanation of the assertion.
  • If the assertion is true but reason is false.
  • If the assertion and reason both are fare.
Assertion : When a gas is allowed to expand, work done by gas is positive.
Reason : Force due to gaseous pressure and displacement (of position) on in the same direction.
  • If both assertion and reason and the reason is the correct explanation of the Assertion.
  • If both assertion and reason are true but reason is not the correct explanation of the assertion.
  • If the assertion is true but reason is false.
  • If the assertion and reason both are fare.
Assertion : A light body and heavy body have same momentum. Then they also have same kinetic energy.
Reason : Kinetic energy does not depend on mass of the body.
  • If both assertion and reason and the reason is the correct explanation of the Assertion.
  • If both assertion and reason are true but reason is not the correct explanation of the assertion.
  • If the assertion is true but reason is false.
  • If the assertion and reason both are fare.
Assertion : Mountain roads rarely go straight up the slope.
Reason : slope of mountains are large, therefore, more chances of vehicle to slip from roads.
  • If both assertion and reason and the reason is the correct explanation of the Assertion.
  • If both assertion and reason are true but reason is not the correct explanation of the assertion.
  • If the assertion is true but reason is false.
  • If the assertion and reason both are fare.

Physics-Work Energy and Power-97630.png
  • If both assertion and reason and the reason is the correct explanation of the Assertion.
  • If both assertion and reason are true but reason is not the correct explanation of the assertion.
  • If the assertion is true but reason is false.
  • If the assertion and reason both are fare.
Assertion : The mass equivalent of 1000 kwh energy is 40 microgram.
Reason : This follows from E = mc2 where C = 3 × 108 m/s
  • If both assertion and reason and the reason is the correct explanation of the Assertion.
  • If both assertion and reason are true but reason is not the correct explanation of the assertion.
  • If the assertion is true but reason is false.
  • If the assertion and reason both are fare.
Assertion : Two bodies of different masses have same momentum. Their kinetic energy are in the inverse ratio of their masses.
Reason : K.E. = 1/2 mv2
  • If both assertion and reason and the reason is the correct explanation of the Assertion.
  • If both assertion and reason are true but reason is not the correct explanation of the assertion.
  • If the assertion is true but reason is false.
  • If the assertion and reason both are fare.
Assertion : Linear momentum is conserved in both, elastic and inelastic collisions.
Reason : Total energy is conserved in all such collisions.
  • If both assertion and reason and the reason is the correct explanation of the Assertion.
  • If both assertion and reason are true but reason is not the correct explanation of the assertion.
  • If the assertion is true but reason is false.
  • If the assertion and reason both are fare.
Assertion : Both, a stretched spring and a compressed spring have potential energy.
Reason : Work is done against the restoring force in each case.
  • If both assertion and reason and the reason is the correct explanation of the Assertion.
  • If both assertion and reason are true but reason is not the correct explanation of the assertion.
  • If the assertion is true but reason is false.
  • If the assertion and reason both are fare.
A body falls freely under the action of gravity from a height h above the ground.
Physics-Work Energy and Power-97631.png
  • a – P, b – Q, c – R, d – S
  • a – Q, b – P, c – S, d – R
  • a – S, b – R, c – Q, d – P
  • a – R, b – S, c – Q, d – P
A body of mass 1 kg is thrown upwards with a velocity 20 m/s. It momentarily comes to rest after attaining a height of 18 m. How much energy is lost due to air friction (g = 10 m / s2)
  • 20 J
  • 30 J
  • 40 J
  • 10 J
. If the unit of force and length each be increased by four times, then the unit of energy is increased by
  • 16 times
  • 8 times
  • 2 times
  • 4 times
A man pushes a wall and fails to displace it. He does
  • Negative work
  • Positive but not maximum work
  • No work at all
  • Maximum work
Which of the following is a scalar quantity
  • Displacement
  • Electric field
  • Acceleration
  • Work
A force of 5N acts on a 15kg body initially at rest. The work done by the force during the first second of motion of the body is
  • 5J
  • 2)
    Physics-Work Energy and Power-97634.png
  • 6J
  • 75J
The work done against gravity in taking 10 kg mass at 1m height in 1 sec will b e
  • 49 J
  • 98 J
  • 196 J
  • None of these
The slope of the kinetic energy versus position vector gives the rate of change of
  • Momentum
  • velocity
  • Force
  • Power
A 50kg man with 20kg load on his head climbs up 20 steps of 0.25 m height each. The work done in climbing is
  • 5 J
  • 350 J
  • 100 J
  • 3430 J
If force and displacement of particle in direction of force are doubled. Work would be
  • Double
  • 4 times
  • Half
  • 1/4 times
A particle moves under the effect of a force F = Cx from x = 0 to x = x1. The work done in the process is

  • Physics-Work Energy and Power-97638.png
  • 2)
    Physics-Work Energy and Power-97639.png
  • Cx1
  • Zero
Which one of the following is not a conservative force
  • Gravitational force
  • Electrostatic force between two charges
  • Magnetic force between two magnetic dipoles
  • Frictional force
If we throw a body upwards with velocity of 4 m/s, at what height does its kinetic energy reduce to half of the initial value (Taking g = 10 ms–1)
  • 4m
  • 2 m
  • 1 m
  • 0.4 m
If a force F is applied on a body and it moves with a velocity v, the power will be
  • F × v
  • F/ v
  • F / v2
  • F × v2
0:0:1


Answered Not Answered Not Visited Correct : 0 Incorrect : 0

Practice Physics Quiz Questions and Answers