Work Power and Energy
505 Questions
Start Allen Test
AIIMS 1998; UPSEAT 2000; JIPMER 2001; Kerala PMT 2004
Q276
Errorless
Conservation of Energy and Momentum
MCQ
A light and a heavy body have equal momenta. Which one has greater K.E
A.
The light body
B.
The heavy body
C.
The K.E. are equal
D.
Data is incomplete
AIIMS 1998, 2002; KCET 2000; CPMT 2003; J & K CET 2004; Kerala PMT 2005; RPMT 2006
Q277
Errorless
Conservation of Energy and Momentum
MCQ
If the K.E. of a particle is doubled, then its momentum will
A.
Remain unchanged
B.
Be doubled
C.
Be quadrupled
D.
Increase $\sqrt{2}$ times
AFMC 1998; RPMT 1999; DPMT 2000; MP PET 2004
Q278
Errorless
Conservation of Energy and Momentum
MCQ
The kinetic energy of a body of mass 3 kg and momentum 2 Ns is
A.
1 J
B.
$\frac{2}{3}J$
C.
$\frac{3}{2}J$
D.
4 J
BHU 1998, 2005; JIPMER 2001, 02; AFMC 2005
Q279
Errorless
Perfectly Inelastic Collision
MCQ
Which of the following is not a perfectly inelastic collision
A.
Striking of two glass balls
B.
A bullet striking a bag of sand
C.
An electron captured by a proton
D.
A man jumping onto a moving cart
JIPMER 1997; CBSE PMT 1999; BHU 2000; RPMT 2000; Odisha JEE 2002
Q280
Errorless
Work Done by Constant Force
MCQ
A body moves a distance of 10 m along a straight line under the action of a force of 5 N. If the work done is 25 joules, the angle which the force makes with the direction of motion of the body is
A.
0°
B.
30°
C.
60°
D.
90°
MP PMT 1997, 2000; JIPMER 2000; AIEEE 2002, 04; DCE 2006
Q281
Errorless
Work Done by Variable Force
MCQ
A uniform chain of length 2m is kept on a table such that a length of 60cm hangs freely from the edge of the table. The total mass of the chain is 4kg. What is the work done in pulling the entire chain on the table
A.
7.2 J
B.
3.6 J
C.
120 J
D.
1200 J
MP PMT 1997; CPMT 1997; DPMT 2001
Q282
Errorless
Conservation of Energy and Momentum
MCQ
If a lighter body (mass $M_{1}$ and velocity $V_{1}$ ) and a heavier body (mass $M_{2}$ and velocity $V_{2}$ ) have the same kinetic energy, then
A.
$M_{2}V_{2} < M_{1}V_{1}$
B.
$M_{2}V_{2} = M_{1}V_{1}$
C.
$M_{2}V_{1} = M_{1}V_{2}$
D.
$M_{2}V_{2} > M_{1}V_{1}$
BHU 1997; MP PET 2000; CBSE PMT 2000; MH CET 2000; JIPMER 2001, 02; AMU (Med.) 2002; DPMT 2003
Q283
Errorless
POWER
MCQ
The power of a pump, which can pump 200kg of water to a height of 200m in 10sec is $(g=10m/s^{2})$
A.
40 kW
B.
80 kW
C.
400 kW
D.
960 kW
MP PMT 1997; CBSE PMT 1998; AIIMS 2000; UPSEAT 2001; MP PET 2001, 02, 07; Kerala PMT 2008
Q284
Errorless
Elastic and Inelastic Collision
MCQ
Two equal masses $m_{1}$ and $m_{2}$ moving along the same straight line with velocities +3 m/s and -5 m/s respectively collide elastically. Their velocities after the collision will be respectively
A.
+4 m/s for both
B.
-3 m/s and +5 m/s
C.
-4 m/s and +4 m/s
D.
-5 m/s and +3 m/s
CPMT 1997; MP PET 1999; DPMT 1999, 2005; JIPMER 2000
Q285
Errorless
Perfectly Inelastic Collision
MCQ
A particle of mass m moving eastward with a speed v collides with another particle of the same mass moving northward with the same speed v. The two particles coalesce on collision. The new particle of mass 2m will move in the north-easterly direction with a velocity
A.
v/2
B.
2v
C.
v/ $\sqrt{2}$
D.
v
CBSE PMT 1997; AIIMS 2001; Pb. PMT 2001; J & K CET 2005; AIEEE 2008
Q286
Errorless
Perfectly Inelastic Collision
MCQ
A body of mass 4 kg moving with velocity 12 m/s collides with another body of mass 6 kg at rest. If two bodies stick together after collision, then the loss of kinetic energy of system is
A.
Zero
B.
288 J
C.
172.8 J
D.
144 J
BHU 1997; J & K CET 2010; CBSE PMT (Pre.) 2011
Q287
Errorless
Graphical Questions
MCQ
Force F on a particle moving in a straight line varies with distance d as shown in the figure. The work done on the particle during its displacement of 12 m
A.
13 J
B.
18 J
C.
21 J
D.
26 J
CBSE PMT 1996; MP PMT/PET 1998; AIIMS 1999; JIPMER 2001, 02; RPMT 2005
Q288
Errorless
Perfectly Inelastic Collision
MCQ
A particle of mass m moving with velocity v strikes a stationary particle of mass 2m and sticks to it. The speed of the system will be
A.
v/2
B.
2v
C.
v/3
D.
3v
Haryana CEE 1996; BVP 2003
Q289
Errorless
Perfectly Inelastic Collision
MCQ
Two putty balls of equal mass moving with equal velocity in mutually perpendicular directions, stick together after collision. If the balls were initially moving with a velocity of $45\sqrt{2} ms^{-1}$ each, the velocity of their combined mass after collision is
A.
$45\sqrt{2} ms^{-1}$
B.
$45ms^{-1}$
C.
$90ms^{-1}$
D.
$22.5\sqrt{2} ms^{-1}$
AFMC 1996, 2006; BHU 2001; DCE 2004, 09; AIIMS 2006; UP CPMT 2006
Q290
Errorless
Perfectly Inelastic Collision
MCQ
In an inelastic collision, what is conserved
A.
Kinetic energy
B.
Momentum
C.
Both a) and b)
D.
Neither a) nor b)
EAMCET (Engg.) 1995; WB-JEE 2009
Q291
Errorless
Conservation of Energy and Momentum
MCQ
Two bodies of masses 2m and m have their K.E. in the ratio 8:1, then their ratio of momenta is
A.
1:1
B.
2:1
C.
4:1
D.
8:1
Manipal MEE 1995; AIEEE 2002, 06; Pb. PET 2004; CBSE PMT 2005; KCET 2007; Odisha JEE 2008
Q292
Errorless
Conservation of Energy and Momentum
MCQ
A bomb of mass 9kg explodes into 2 pieces of mass 3kg and 6kg. The velocity of mass 3kg is 1.6 m/s, the K.E. of mass 6kg is
A.
3.84 J
B.
9.6 J
C.
1.92 J
D.
2.92 J
CBSE PMT 1995; AIEEE 2003
Q293
Errorless
Elastic and Inelastic Collision
MCQ
A $^{238}U$ nucleus decays by emitting an alpha particle of speed $v \, ms^{-1}$ . The recoil speed of the residual nucleus is (in $ms^{-1}$ )
A.
-4v / 234
B.
v / 4
C.
-4v / 238
D.
4v / 238
BHU 1995; MP PET 1996; AMU (Med.) 1999; JIPMER 2000; JEE (Main) 2021
Q294
Errorless
Critical Thinking
MCQ
A body is moved along a straight line by a machine delivering constant power. The distance moved by the body in time t is proportional to
A.
$t^{1/2}$
B.
$t^{3/4}$
C.
$t^{3/2}$
D.
$t^{2}$
Q295
Allen
WORK
MCQ
A force $\vec{\mathrm{F}} = (4\hat{\mathrm{i}} - 4\hat{\mathrm{j}} - 2\hat{\mathrm{k}})\mathrm{N}$ displaces a particle by $\vec{\mathrm{d}} = (3\hat{\mathrm{i}} + 2\hat{\mathrm{j}} - 2\hat{\mathrm{k}})\mathrm{m}$ , calculate work done.
A.
Zero
B.
8 J
C.
4 J
D.
12 J
Q296
Allen
WORK
MCQ
A force $\vec{\mathrm{F}} = (3\hat{\mathrm{i}} + 2\hat{\mathrm{j}})\mathrm{N}$ acts on a body and produces a displacement $\vec{\mathrm{S}} = (4\hat{\mathrm{i}} - \hat{\mathrm{j}} + 3\hat{\mathrm{k}})\mathrm{m}$ . The work done will be
A.
$13\mathrm{J}$
B.
$30\mathrm{J}$
C.
$10\mathrm{J}$
D.
$20\mathrm{J}$
Q297
Allen
WORK
MCQ
A particle is moved from a position $\vec{r}_1 = (2\hat{i} + \hat{j} - 2\hat{k})$ metre to a position $\vec{r}_2 = (4\hat{i} + 3\hat{j} - \hat{k})$ metre under the action of a force $\vec{F} = (3\hat{i} + 2\hat{j} + 2\hat{k})$ N. The work done is equal to:
A.
$32\mathrm{J}$
B.
$12\mathrm{J}$
C.
$24\mathrm{J}$
D.
$16\mathrm{J}$
Q298
Allen
WORK
MCQ
A body of mass m is displaced from point A(3, 1, 3) m to point B(1, 2, 1) m under the effect of a force $\vec{\mathrm{F}} = (5\hat{\mathrm{i}} + 2\hat{\mathrm{j}} - 4\hat{\mathrm{k}})$ , calculate work done by the force.
A.
57 J
B.
11 J
C.
0
D.
22 J
Q299
Allen
WORK
MCQ
A person of mass m is standing on one end of a plank of mass M and length L floating in water. The person moves from one end to another and stops. Work done by normal force is –
A.
MgL
B.
mgL
C.
$\frac{mMgL}{M+m}$
D.
0
Q300
Allen
WORK
MCQ
The work done against gravity in taking 5 kg.
mass to 2 m height in 1 s will be :-
A.
49 J
B.
98 J
C.
196 J
D.
None of these







