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Work, Power & Energy

769 Questions Start Allen Test
All Exams Allen Advance Errorless
AIEEE 2004 Q276 Errorless Work Done by Variable Force MCQ
A particle moves in a straight line with retardation proportional to its displacement. Its loss of kinetic energy for any displacement $x$ is proportional to
A.
$x^2$
B.
$e^x$
C.
$x$
D.
$\log_e x$
UPSEAT 2004 Q277 Errorless Conservation of Energy and Momentum MCQ
An object of mass 3m splits into three equal fragments. Two fragments have velocities $v\hat{j}$ and $v\hat{i}$ . The velocity of the third fragment is
A.
$v(\hat{j}-\hat{i})$
B.
$v(\hat{i}-\hat{j})$
C.
$-v(\hat{i}+\hat{j})$
D.
$\frac{v(\hat{i}+\hat{j})}{\sqrt{2}}$
AFMC 2004; Odisha JEE 2008 Q278 Errorless Conservation of Energy and Momentum MCQ
A rifle bullet loses $1/20^{\text{th}}$ of its velocity in passing through a plank. The least number of such planks required just to stop the bullet is
A.
5
B.
10
C.
11
D.
20
DCE 2004 Q279 Errorless Conservation of Energy and Momentum MCQ
A bomb is kept stationary at a point. It suddenly explodes into two fragments of masses 1 g and 3 g. The total K.E. of the fragments is $6.4 \times 10^{4}$ J. What is the K.E. of the smaller fragment
A.
$2.5 \times 10^{4}$ J
B.
$3.5 \times 10^{4}$ J
C.
$4.8 \times 10^{4}$ J
D.
$5.2 \times 10^{4}$ J
Pb. PET 2004 Q280 Errorless Conservation of Energy and Momentum MCQ
If a shell fired from a cannon, explodes in mid air, then
A.
Its total kinetic energy increases
B.
Its total momentum increases
C.
Its total momentum decreases
D.
None of these
DCE 2004 Q281 Errorless Conservation of Energy and Momentum MCQ
A body is moving with a velocity v, breaks up into two equal parts. One of the part retraces back with velocity v. Then the velocity of the other part is
A.
v in forward direction
B.
3v in forward direction
C.
v in backward direction
D.
3v in backward direction
CBSE PMT 2004 Q282 Errorless Conservation of Energy and Momentum MCQ
A ball of mass 2kg and another of mass 4kg are dropped together from a 60 feet tall building. After a fall of 30 feet each towards earth, their respective kinetic energies will be in the ratio of
A.
$\sqrt{2}:1$
B.
1:4
C.
1:2
D.
$1:\sqrt{2}$
KCET 2004 Q283 Errorless Conservation of Energy and Momentum MCQ
A bullet moving with a speed of $100 \, ms^{-1}$ can just penetrate two planks of equal thickness. Then the number of such planks penetrated by the same bullet when the speed is doubled will be
A.
4
B.
8
C.
6
D.
10
AIEEE 2004; BHU 2006 Q284 Errorless Power MCQ
A body of mass m accelerates uniformly from rest to $v_{1}$ in time $t_{1}$ . As a function of time t, the instantaneous power delivered to the body is
A.
$\frac{mv_{1}t}{t_{1}}$
B.
$\frac{mv_{1}^{2}t}{t_{1}}$
C.
$\frac{mv_{1}t^{2}}{t_{1}}$
D.
$\frac{mv_{1}^{2}t}{t_{1}^{2}}$
UPSEAT 2004 Q285 Errorless Elastic and Inelastic Collision MCQ
Four smooth steel balls of equal mass at rest are free to move along a straight line without friction. The first ball is given a velocity of 0.4 m/s. It collides head on with the second elastically, the second one similarly with the third and so on. The velocity of the last ball is
A.
0.4m/s
B.
0.2m/s
C.
0.1m/s
D.
0.05m/s
DCE 2004 Q286 Errorless Elastic and Inelastic Collision MCQ
Two balls at same temperature collide. What is conserved
A.
Temperature
B.
Velocity
C.
Kinetic energy
D.
Momentum
BCECE 2004; J & K CET 2006 Q287 Errorless Elastic and Inelastic Collision MCQ
A body of mass M moves with velocity v and collides elastically with a another body of mass m (M>>m) at rest then the velocity of body of mass m is
A.
v
B.
2v
C.
v/2
D.
Zero
IIT-JEE (Screening) 2004; J & K CET 2006 Q288 Errorless Graphical Questions MCQ
A particle is placed at the origin and a force $F = kx$ is acting on it (where $k$ is positive constant). If $U(0) = 0$ , the graph of $U(x)$ versus $x$ will be (where $U$ is the potential energy function)
A.
B.
C.
D.
IIT-JEE 2004 Q289 Advance ARCHIVE: JEE ADVANCED MCQ
A particle is placed at the origin and a force $F = kx$ is acting on it (where $k$ is a positive constant). If $U(0) = 0$ , the graph of $U(x)$ versus $x$ will be: (where $U$ is the potential energy function)
A.
B.
C.
D.
MP PET 2003 Q290 Errorless Work Done by Constant Force MCQ
A body of mass 5 kg is placed at the origin, and can move only on the x-axis. A force of 10 N is acting on it in a direction making an angle of $60^{\circ}$ with the x-axis and displaces it along the x-axis by 4 metres. The work done by the force is
A.
2.5 J
B.
7.25 J
C.
40 J
D.
20 J
MP PET 2003 Q291 Errorless Conservation of Energy and Momentum MCQ
The potential energy of a weight less spring compressed by a distance $a$ is proportional to
A.
$a$
B.
$a^2$
C.
$a^{-2}$
D.
$a^0$
CBSE PMT 2003; KCET 2012 Q292 Errorless Conservation of Energy and Momentum MCQ
A stationary particle explodes into two particles of a masses $m_{1}$ and $m_{2}$ which move in opposite directions with velocities $v_{1}$ and $v_{2}$ . The ratio of their kinetic energies $E_{1}/E_{2}$ is
A.
$m_{1}/m_{2}$
B.
1
C.
$m_{1}v_{2}/m_{2}v_{1}$
D.
$m_{2}/m_{1}$
IIT-JEE (Screening) 2003 Q293 Errorless Critical Thinking MCQ
If $W_{1}, W_{2}$ and $W_{3}$ represent the work done in moving a particle from A to B along three different paths 1, 2 and 3 respectively (as shown) in the gravitational field of a point mass m, find the correct relation between $W_{1}, W_{2}$ and $W_{3}$
A.
$W_{1} > W_{2} > W_{3}$
B.
$W_{1} = W_{2} = W_{3}$
C.
$W_{1} < W_{2} < W_{3}$
D.
$W_{2} > W_{1} > W_{3}$
MP PMT 2003 Q294 Errorless Critical Thinking MCQ
A lorry and a car moving with the same K.E. are brought to rest by applying the same retarding force, then
A.
Lorry will come to rest in a shorter distance
B.
Car will come to rest in a shorter distance
C.
Both come to rest in a same distance
D.
None of the above
AIEEE 2003 Q295 Errorless Critical Thinking MCQ
Consider the following two statements 1 Linear momentum of a system of particles is zero 2 Kinetic energy of a system of particles is zero, Then
A.
1 implies 2 and 2 implies 1
B.
1 does not imply 2 and 2 does not imply 1
C.
1 implies 2 but 2 does not imply 1
D.
1 does not imply 2 but 2 implies 1
IIT-JEE 2003 Q296 Advance ARCHIVE: JEE ADVANCED MCQ
If $W_{1}$ , $W_{2}$ and $W_{3}$ represent the work done in moving a particle from A to B along three different paths 1, 2 and 3 respectively (as shown) in the gravitational field of a point mass m. Find the correct relation between $W_{1}$ , $W_{2}$ and $W_{3}$
A.
$W_{1} > W_{2} > W_{3}$
B.
$W_{1}=W_{2}=W_{3}$
C.
$W_{1} < W_{2} < W_{3}$
D.
$W_{2} > W_{1} > W_{3}$
MP PMT 2002; CBSE PMT 2003, 06; UPSEAT 2004; Odisha PMT 2004; WB-JEE 2012 Q297 Errorless Work Done by Variable Force MCQ
If a long spring is stretched by 0.02 m, its potential energy is U. If the spring is stretched by 0.1 m, then its potential energy will be
A.
$\frac{U}{5}$
B.
U
C.
5U
D.
25U
Pb. PMT 2002; J & K CET 2004 Q298 Errorless Conservation of Energy and Momentum MCQ
A body moving with velocity v has momentum and kinetic energy numerically equal. What is the value of v
A.
2m/s
B.
$\sqrt{2}$ m/s
C.
1m/s
D.
0.2 m/s
AIEEE 2002; DCE 2002; BCECE 2006; WB-JEE 2012 Q299 Errorless Conservation of Energy and Momentum MCQ
If a body looses half of its velocity on penetrating $3\mathrm{cm}$ in a wooden block, then how much will it penetrate more before coming to rest
A.
$1\mathrm{cm}$
B.
$2\mathrm{cm}$
C.
$3\mathrm{cm}$
D.
$4\mathrm{cm}$
Kerala PET 2002; CBSE PMT (Mains) 2010 Q300 Errorless Power MCQ
A particle of mass M starting from rest undergoes uniform acceleration. If the speed acquired in time T is V, the power delivered to the particle is
A.
$\frac{MV^{2}}{T}$
B.
$\frac{1}{2}\frac{MV^{2}}{T^{2}}$
C.
$\frac{MV^{2}}{T^{2}}$
D.
$\frac{1}{2}\frac{MV^{2}}{T}$