← Back to Physics-I

Work Power and Energy

267 Questions Start Errorless Test
All Exams Allen Objective Errorless
Kerala PET 2010 Q101 Errorless 4. Power MCQ
A force $(4\hat{i} + \hat{j} - 2\hat{k})N$ acting on a body maintains its velocity at $(2\hat{i} + 2\hat{j} + 3\hat{k})ms^{-1}$ . The power exerted is
A.
4 W
B.
5 W
C.
2 W
D.
8 W
E.
1 W
AMU (Med.) 2010 Q102 Errorless 5. Elastic and Inelastic Collision MCQ
A billiards player hits a stationary ball by an identical ball to pocket the target ball in a corner pocket that is at an angle of $35^{\circ}$ with respect to the direction of motion of the first ball. Assuming the collision as elastic and that friction and rotational motion are not important, the angle made by the target ball with respect to the incoming ball is
A.
$35^{\circ}$
B.
$50^{\circ}$
C.
$55^{\circ}$
D.
$60^{\circ}$
J & K CET 2010 Q103 Errorless 5. Elastic and Inelastic Collision MCQ
Three identical spherical balls $A, B$ and $C$ are placed on a table as shown in the figure along a straight line. $B$ and $C$ are at rest initially. The ball A hits B head on with a speed of $10 \, m \, s^{-1}$ . Then after all collisions (assumed to be elastic) A and B are brought to rest and C takes off with a velocity of
A.
$5 \, m \, s^{-1}$
B.
$10 \, m \, s^{-1}$
C.
$2.5 \, m \, s^{-1}$
D.
$7.5 \, m \, s^{-1}$
Odisha JEE 2010 Q104 Errorless 5. Elastic and Inelastic Collision MCQ
In an inelastic collision
A.
Only momentum is conserved
B.
Only kinetic energy is conserved
C.
Neither momentum nor kinetic energy is conserved
D.
Both momentum and kinetic energy are conserved
CBSE PMT 2010 Q105 Errorless 5. Elastic and Inelastic Collision MCQ
A ball moving with velocity 2 m/s. collides head on with another stationary ball of double the mass. If the coefficient of restitution is 0.5, then their velocities (in m/s) after collision will be
A.
0, 2
B.
0, 1
C.
1, 1
D.
1, 0.5
Kerala PMT 2010 Q106 Errorless 7. Critical Thinking MCQ
The potential energy of a conservative system is given by $V(x) = (x^{2} - 3x)$ joule. Then its equilibrium position is at
A.
x = 1.5 m
B.
x = 2 m
C.
x = 2.5 m
D.
x = 3 m
E.
x = 0.33 m
IIT-JEE 2010 Q107 Errorless 8. Graphical Questions MCQ
A block of mass 2 kg is free to move along the x-axis. It is at rest and from t = 0 onwards it is subjected to a time-dependent force $F(t)$ in the x-direction. The force $F(t)$ varies with t as shown in the figure. The kinetic energy of the block after 4.5 seconds is
A.
4.50 J
B.
7.50 J
C.
5.06 J
D.
14.06 J
AIIMS 2010 Q108 Errorless 9. Assertion and Reason MCQ
Assertion : The change in kinetic energy of a particle is equal to the work done on it by the net force. Reason : Change in kinetic energy of particle is equal to the work done only in case of a system of one particle.
A.
If both assertion and reason are true and the reason is the correct explanation of the assertion.
B.
If both assertion and reason are true but reason is not the correct explanation of the assertion.
C.
If assertion is true but reason is false.
D.
If the assertion and reason both are false.
E.
If assertion is false but reason is true.
CBSE PMT 2009 Q109 Errorless 1. Work Done by Constant Force MCQ
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 ( $g = 10 \, m/s^{2}$ )
A.
20 J
B.
30 J
C.
40 J
D.
10 J
AMU PMT 2009 Q110 Errorless 3. Conservation of Energy and Momentum MCQ
A ball is projected vertically upwards with a certain initial speed. Another ball of the same mass is projected at an angle of $60^{\circ}$ with the vertical with the same initial speed. At highest points of their journey, the ratio of their potential energies will be
A.
1:1
B.
2:1
C.
3:2
D.
4:1
EAMCET 2009 Q111 Errorless 3. Conservation of Energy and Momentum MCQ
A bullet of mass 0.02 kg travelling horizontally with velocity $250 \, ms^{-1}$ strikes a block of wood of mass 0.23 kg which rests on a rough horizontal surface. After the impact, the block and bullet move together and come to rest after travelling a distance of 40m. The coefficient of sliding friction of the rough surface is ( $g = 9.8 \, ms^{-2}$ )
A.
0.75
B.
0.61
C.
0.51
D.
0.30
EAMCET 2009 Q112 Errorless 4. Power MCQ
A motor of power $p_{0}$ is used to deliver water at a certain rate through a given horizontal pipe. To increase the rate of flow of water through the same pipe n times, the power of the motor is increased to $p_{1}$ . The ratio of $p_{1}$ to $p_{0}$ is
A.
n:1
B.
$n^{2}:1$
C.
$n^{3}:1$
D.
$n^{4}:1$
IIT-JEE 2009 Q113 Errorless 5. Elastic and Inelastic Collision MCQ
Three objects A, B and C are kept in a straight line on a frictionless horizontal surface. These have masses m, 2m and m, respectively. The object A moves towards B with a speed 9 m/s and makes an elastic collision with it. Thereafter, B makes completely inelastic collision with C. All motions occur on the same straight line. Find the final speed (in m/s) of the object C
A.
3 m/s
B.
4 m/s
C.
5 m/s
D.
1 m/s
IIT-JEE 2009 Q114 Errorless 7. Critical Thinking MCQ
A light inextensible string that goes over a smooth fixed pulley as shown in the figure connects two blocks of masses 0.36 kg and 0.72 kg. Taking $g = 10 \, m/s^{2}$ , find the work done (in joules) by the string on the block of mass 0.36 kg during the first second after the system is released from rest
A.
6 Joule
B.
5 Joule
C.
8 Joule
D.
2 Joule
IIT-JEE 2009 Q115 Errorless 7. Critical Thinking MCQ
Two small particles of equal masses start moving in opposite directions from a point A in a horizontal circular orbit. Their tangential velocities are v and 2v, respectively, as shown in the figure. Between collisions, the particles move with constant speeds. After making how many elastic collisions, other than that at A, these two particles will again reach the point A
A.
4
B.
3
C.
2
D.
1
Kerala PET 2009 Q116 Errorless 8. Graphical Questions MCQ
A particle is acted upon by a force F which varies with position x as shown in figure. If the particle at x = 0 has kinetic energy of 25 J, then the kinetic energy of the particle at $x = 16m$ is
A.
45 J
B.
30 J
C.
70 J
D.
135 J
E.
20 J
KCET 2009 Q117 Errorless 8. Graphical Questions MCQ
The work done by a force acting on a body is as shown in the graph. The total work done in covering an initial distance of 20 m is
A.
225 J
B.
200 J
C.
400 J
D.
175 J
WB-JEE 2009 Q118 Errorless 8. Graphical Questions MCQ
The force $F$ acting on a particle moving in a straight line is shown in figure. What is the work done by the force on the particle in the $1^{\text{st}}$ meter of the trajectory $x(\mathrm{in} \mathrm{m}) \longrightarrow$
A.
5 J
B.
10 J
C.
15 J
D.
2.5 J
AIEEE 2009 Q119 Errorless 8. Graphical Questions MCQ
Consider a rubber ball freely falling from a height h=4.9m onto a horizontal elastic plate. Assume that the duration of collision is negligible and the collision with the plate is totally elastic. Then the velocity as a function of time and the height as a function of time will be
A.

B.

C.

D.

DUMET 2009 Q120 Errorless 10. Self Evaluation Test MCQ
A ball moves in a frictionless inclined table without slipping. The work done by the table surface on the ball is
A.
Positive
B.
Negative
C.
Zero
D.
None of these
AMU PMT 2009 Q121 Errorless 10. Self Evaluation Test MCQ
Identify the wrong statement
A.
A body can have momentum without energy
B.
A body can have energy without momentum
C.
The momentum is conserved in an elastic collision
D.
Kinetic energy is not conserved in an inelastic collision
MP PET 2009 Q122 Errorless 10. Self Evaluation Test MCQ
A neutron travelling with a velocity v and K.E. E collides perfectly elastically head on with the nucleus of an atom of mass number A at rest. The fraction of total energy retained by neutron is
A.
$\left(\frac{A-1}{A+1}\right)^{2}$
B.
$\left(\frac{A+1}{A-1}\right)^{2}$
C.
$\left(\frac{A-1}{A}\right)^{2}$
D.
$\left(\frac{A+1}{A}\right)^{2}$
WB-JEE 2008 Q123 Errorless 2. Work Done by Variable Force MCQ
A wire is stretched under a force. If the wire suddenly snaps the temperature of the wire
A.
Remains the same
B.
Decreases
C.
Increases
D.
First decreases then increases
Kerala PET 2008 Q124 Errorless 3. Conservation of Energy and Momentum MCQ
Two bodies A and B have masses 20 kg and 5 kg respectively. Each one is acted upon by a force of 4 kg wt. If they acquire the same kinetic energy in times $t_{A}$ and $t_{B}$ , then the ratio $\frac{t_{A}}{t_{B}}$ is
A.
1/2
B.
2
C.
2/5
D.
5/6
E.
1/5
Kerala PET 2008 Q125 Errorless 3. Conservation of Energy and Momentum MCQ
A spring gun of spring constant 90 N/cm is compressed 12 cm by a ball of mass 16 g. If the trigger is pulled, the velocity of the ball is
A.
$50 \, ms^{-1}$
B.
$9 \, ms^{-1}$
C.
$40 \, ms^{-1}$
D.
$60 \, ms^{-1}$
E.
$90 \, ms^{-1}$