CBSE Questions for Class 11 Medical Physics Work, Energy And Power Quiz 2 - MCQExams.com

What is potential energy?
  • Energy of an object due to its position or arrangement in a system
  • Energy of an object due to its nature or arrangement in a system
  • Energy of an object due to its shape or arrangement in a system
  • None
State whether the given statement is True or False :
The potential energy of a free falling object decreases progressively.
  • True
  • False
A body of mass 0.1 kg is dropped from a height of 10 m at a place wheres $$g= 10\, m\, s^{-2}$$. Its KE just before its strikes the ground is:
  • 1 J
  • 1.04 J
  • 3.5 J
  • 10 J
A ball with mass m and speed $$V_0$$ hit a wall and rebounds back with same speed.
Calculate the change in the object's kinetic energy.
  • $$-mv_0 ^2$$
  • $$- \frac{1}{2}mv_0 ^2$$
  • Zero
  • $$ \frac{1}{2}mv_0 ^2$$
  • $$mv_0 ^2$$
Mechanical energy is the form of which two energies:
  • Potential and Kinetic
  • Thermal and Nuclear
  • Potential and Sound
  • Light and Sound
What is kinetic energy?
  • Energy possessed by a body by the virtue of its motion
  • Energy possessed by a body by the virtue of its shape
  • Energy possessed by a body by the virtue of its size
  • None
Refer to the given figures and select the correct option regarding these, when they are operating.
810079_4788dbd4dd4c4526b0b5b52ab4209d91.jpg
  • Object I converts mechanical energy into kinetic energy whereas object II converts electrical energy into potential energy
  • Object II converts electrical energy into kinetic, heat and sound energy
  • Object I converts potential energy into kinetic energy
  • Both B and C
A force of $$16N$$ is distributed uniformly on one surface of a cube of edge $$8cm$$. The pressure on this surface is 
  • $$3500Pa$$
  • $$2500Pa$$
  • $$4500Pa$$
  • $$5500Pa$$
If amount of heat supplied is Q, work done is W and change in internal energy is $$mC_V dT$$, then relation among them is $$(C_V$$ gram specific heat)
  • $$mC_V dT = Q + W$$
  • $$Q = W + mC_V dT$$
  • $$Q + mC_V dT = W$$
  • None of these
A child builds a tower from three blocks. The blocks are uniform cubes of side $$2cm$$. The blocks are initially lying on the same horizontal surface and each block has a mass of $$0.1kg$$. The work done by the child is (in J)
  • $$4$$
  • $$0.04$$
  • $$6$$
  • $$0.06$$
A bread gives a boy of mass $$40kg$$ an energy of $$21kJ$$. If the efficiency is $$28$$% then the height can be climbed by him using this energy is:
  • $$5 cm$$
  • $$10 cm$$
  • $$15 cm$$
  • $$20 cm$$
In the phenomenon of work done by variable forces, the forces:
  • remain constant
  • don't remain constant
  • increase
  • decrease
Work-energy theorem is valid in the presence of
  • External forces only
  • Internal forces onlhy
  • Conservative forces only
  • All type of forces
The velocity of the block after covering $$3m$$ distance under the influence of 12 N force :
  • $$12m/s$$
  • $$6m/s$$
  • $$3.5m/s$$
  • $$3m/s$$
A particle moves from $$X = 0\ $$ to $$X = 2\ m$$ on X-axis under the effect of $$ { F } (x) = ({ 4x }^{ 3 } - { 3x }^{ 2 } + 2x + 5)\widehat { i } $$ Newton. The work done on the particle is 
  • $$ 22\ Joule$$
  • $$ 36\ Joule$$
  • $$ 46\ Joule$$
  • None of these
Which of the following statements are correct
  • Collision does not require physical contact
  • Collision between sub atomic particles is elastic
  • Collision between macroscopic bodies is generally inelastic
  • None of these
A force F = $$-\frac{K}{X^2} (X \neq 0)$$ acts on a particle in x-direction. The work done by this force in displacing the particle from x = +a to x = +2a is. (Where k is a positive constant)
  • $$\frac{-k}{2a}$$
  • $$\frac{+k}{2a}$$
  • $$\frac{k}{a}$$
  • $$-\frac{k}{a}$$
A $$\vec{F}=(5\hat{i}+3\hat{j}+2\hat{k})\ N$$ is applied over a particle with displaces it from its origin to the point $$\vec{r}=(2\hat{i}-\hat{j})m$$. The work done on the particle is joule is
  • $$-7\ J$$
  • $$+7\ J$$
  • $$+10\ J$$
  • $$13\ J$$
If the resultant force on a system of particles is non-zero, then:
  • The linear momentum of the system must increase
  • The velocity of the centre of mass of the system must change.
  • The distance of the centre of mass may remain constant from a fixed point.
  • Kinetic energy of all particles must either increase simultaneously or decrease simultaneously.
Choose one more correct alternatives.
 For work to be performed , energy must be _____
  • transferred from one place to another
  • concentrated
  • transformed from one type to another
  • destroyed
A ball is at rest at the top of a hill. It rolls down the hill. At the bottom of the hill the ball hits a wall and stops.
Which energy changes occur?
  • Gravitational potential energy $$\rightarrow$$ internal energy $$\rightarrow$$ kinetic energy
  • Gravitational potential energy $$\rightarrow$$ kinetic energy $$\rightarrow$$ internal energy
  • Kinetic energy $$\rightarrow$$ gravitational potential energy $$\rightarrow$$ internal energy
  • Kinetic energy $$\rightarrow$$ internal energy $$\rightarrow$$ gravitational potential energy
A ball of mass $$'m'$$ moves towards a wall with a velocity $$'u'$$, the direction of motion making an angle $$\theta$$ with the surface of the wall and rebounds with the same period. The change in momentum of the ball during the collision is:
  • $$2mu\  sin$$$$\theta$$ towards the wall
  • $$2mu \ sin$$$$\theta$$ away from the wall
  • $$2mu\  cos$$$$\theta$$ towards the wall
  • $$2mu\  cos$$$$\theta$$ away from the wall
 A car of mass 400 kg travelling at 72 kmph crashes a truck of mass 4000 kg and travelling at 9 kmph in the same direction. The car bounces back with a speed of 18 kmph. The speed of the truck after the impact is
  • 9 kmph
  • 18 kmph
  • 27 kmph
  • 36 kmph
A particle moves under the effect of a force $$F = C x$$ from $$x = 0$$ to $$ x = x_{1}$$. The work done in the process is (treat $$C$$ as a constant):
  • $$ \dfrac {C^{2}}{x^{2}_{1}}$$
  • $$Cx^{2}_{1}$$
  • $$ \dfrac {Cx^{2}_{1}}{2}$$
  • $$ \dfrac {C}{x^{2}_{1}}$$
 A perfectly elastic ball $$p_{1}$$of mass 'm' moving with velocity v collides elastically with three exactly similar balls $$p_{2}$$ , $$p_{3}$$ , $$p_{4}$$  lying on a smooth table. Velocities of the four balls after collision are

Image_p3.png
  • 0,0,0,0
  • v,v,v,v
  • v,v,v,0
  • 0,0,0,v
A ball of mass M moving with a velocity V collides head on elastically with another of same mass but moving with a velocity v in the opposite direction. After collision,
  • the velocities are exchanged between the two balls
  • both the balls come to rest
  • both of them move at right angles to the original line of motion
  • one ball comes to rest and another ball travels back with velocity 2V
 A heavy steel ball of mass greater than 1 kg moving with a speed of 2m/ s collides head on with a stationary ping pong ball of mass less than 0.1 g. The collision is elastic. After the collision the ping pong ball moves approximately with a speed
  • $$ 2 m / s $$
  • $$4 m/ s$$
  • $$2\times10^{4}m / s$$
  • $$2\times10^{3}m / s$$
Which of the following physical quantities is different from others?
  • Work
  • Kinetic energy
  • Force
  • Potential energy
A man of mass $$60 kg$$ climbs up a $$ 20 m $$ long staircase on the top of a building $$10 m$$ high. What is the work done by him? $$(Take  g = 10  m  s^{-2})$$
  • $$12 kJ$$
  • $$6 kJ$$
  • $$3 kJ$$
  • $$18 kJ$$
An empty truck moving on a straight road with a certain velocity can be stopped over a distance $$s$$ by applying the brakes. If the truck is loaded so that its mass now is one and half times that of the empty truck and is moving with the same velocity, it can be stopped by the brakes in a distance of (assume that the same braking force is acting in the two cases)
  • $$\dfrac{s}{2}$$
  • $$2 s$$
  • $$\dfrac{3s}{2}$$
  • $$\dfrac{2s}{3}$$
 A heavier body moving with certain velocity collides head on elastically with a lighter body at rest. Then
  • smaller body continues to be in the same state of rest
  • smaller body starts to move in the same direction with same velocity as that of bigger body
  • the smaller body starts to move with twice the velocity of the bigger body in the same direction
  • the bigger body comes to rest
A rain drop of mass (1/10) gram falls vertically at constant speed under the influence of the forces of gravity and viscous drag. In falling through 100 m, the work done by gravity is
  • 0.98 J
  • 0.098 J
  • 9.8 J
  • 98 J
A body of mass $$1$$ $$kg$$ is made to travel with a uniform acceleration of $$30\ cm/s^{2}$$ over a distance of $$2$$ $$m$$, the work done is:
  • $$6 J$$
  • $$60 J$$
  • $$0.6 J$$
  • $$0.3 J$$
lf the two bodies moving at right angles collide and their initial momenta are $$\vec{\mathrm{P}}_{1}$$ and $$\vec{\mathrm{P}}_{2}$$, their resultant momentum after collison is :
  • $$\vec{\mathrm{P}_{1}}-\vec{\mathrm{P}}_{2}$$
  • $$\vec{\mathrm{P}}_{1}\sim\vec{\mathrm{P}}_{2}$$
  • $$\sqrt{\vec{\mathrm{P}_{1}}^{2}+\vec{\mathrm{P}}_{2}^{2}}$$
  • $$\sqrt{\vec{\mathrm{P}_{1}}^{2}-\vec{\mathrm{P}}_{2}^{2}}$$
 A ball moving with a speed of 2.2 m/sec strikes an identical stationary ball. After collision the first ball moves at 1.1 m/sec at $$60^{0}$$  with the original line of motion. The magnitude and direction of the ball after collision is 
  • $$5 m/sec,90^{0}$$
  • $$2 m/sec,60^{0}$$
  • $$\sqrt{39(1.1)}m/sec,30^{0}$$
  • $$10m/sec,60^{0}$$
A 50 gm ball collides with another ball of mass 150gm, moving in its direction of motion, After collision the two balls move at a an angle $$30^{0}$$ with their initial direction. Ratio of their velocities after collision is
  • 3 : 1
  • 1 : 3
  • 2 : 3
  • 1 : 1
The total work done on a particle is equal to the change in its kinetic energy.
This statement is true for which of the condition?
  • always
  • only if the forces acting on the body are conservative
  • only if the forces acting on the body are gravitational
  • only if the forces acting on the body are elastic.
A car is accelerated on a leveled road and attains a velocity 4 times of its initial velocity. In this process the potential energy of the car
  • does not change
  • becomes twice to that of initial
  • becomes 4 times that of initial
  • becomes 16 times that of initial
An 800 g ball is pulled up a slope as shown in the diagram. Calculate the potential energy it gains.

85197.jpg
  • 1.96 J
  • 1.568 J
  • 7.84 J
  • 1.225 J
 A body of mass 5 kg moving with a speed of $$ 3 ms^{-1}$$ collides head on with a body of mass 3 kg moving in the opposite direction at a speed of $$2 ms^{-1}$$. The first body stops after the collision. Find the final velocity of the second body.
  • $$3 ms^{-1}$$
  • $$5 ms^{-1}$$
  • $$-9 ms^{-1}$$
  • $$30 ms^{-1}$$
A body of mass 'm' moving with certain velocity collides with another identical body at rest. If the collision is perfectly elastic and after the collision, if both the bodies move, they can move
  • in the same direction
  • in opposite direction
  • in perpendicular direction
  • making $$45^o$$ to each other
 A ball strikes a horizontal floor at an angle $$45^{0}$$ The value of 'e' between the ball and the floor is 1/Find the fraction of K.E. loss during the collision
  • $$\dfrac{3}{4}$$
  • $$\dfrac{5}{8}$$
  • $$\dfrac{3}{8}$$
  • $$\dfrac{7}{8}$$
 A wagon of mass 10 tons moving at a speed of 12 kmph collides with another wagon of mass 8 tons moving on the same track in the same direction at a speed of 10 kmph. If the speed of the first wagon decreases to 8 kmph. Find the speed of the other after collision
  • 18 kmph
  • 25 kmph
  • 5 kmph
  • 15 kmph
A particle of mass m has a velocity $$-v_{0}\hat{i}$$. while a second particle of same mass has a velocity $$v_{0}j$$. After the particles collide, first particle is found to have a velocity $$\dfrac{-1}{2}v_{0}\hat{i}$$ then the velocity of other particle is
  • $$\dfrac{-1}{2}v_{0}\hat{i}+v_{0}\hat{j}$$
  • $$\dfrac{1}{2}v_{0}\hat{i}+v_{0}\hat{j}$$
  • $$v_{0}\hat{i}+v_{0}\hat{j}$$
  • $$-v_{0}\hat{i}+v_{0}\hat{j}$$
 A 6 kg mass travelling at $$2.5$$ ms$$^{-1}$$ collides head on with a stationary 4 kg mass. After the collision the 6 kg mass travels in its original direction with a speed of $$1$$ ms$$^{-1}$$. The final velocity of 4 kg mass
  • $$1$$ ms$$^{-1}$$
  • $$2.25$$ ms$$^{-1}$$
  • $$2$$ ms$$^{-1}$$
  • $$0$$ ms$$^{-1}$$
A coconut fruit hanging high in a palm tree has ......... owing to its location.
  • Free energy
  • Kinetic energy
  • Activation energy
  • Potential energy
The decrease in the PE of a ball of mass 20 kg which falls from a height of 25 cm is 98 J.
  • True
  • False
When velocity of a moving object is doubled its:
  • acceleration is doubled
  • momentum becomes four times more
  • kinetic energy is increased to four times
  • potential energy is increased
Water stored in a dam possesses:
  • no energy
  • electrical energy
  • kinetic energy
  • potential energy
Two satellites of earth,  $$S_{1}$$ and  $$S_{2}$$, are moving in
the same orbit. The mass of  $$S_{1}$$ is four times the
mass of  $$S_{2}$$. Which one of the following statements is true ?
  • The kinetic energies of the two satellites are

    equal
  • The time period of $$S_{1}$$ is four times that of $$S_{2}$$
  • The potential energies of earth and satellite in

    the two cases are equal
  • $$S_{1}$$ and $$S_{2}$$ are moving with the same speed
0:0:1


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