← Back to Physics-I

Work, Power & Energy

238 Questions Start Errorless Test
All Exams Allen Advance Errorless
IIT-JEE (Screening) 2003 Q201 Errorless 7. 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 Q202 Errorless 7. 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 Q203 Errorless 7. 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
MP PMT 2002; CBSE PMT 2003, 06; UPSEAT 2004; Odisha PMT 2004; WB-JEE 2012 Q204 Errorless 2. 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 Q205 Errorless 3. 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 Q206 Errorless 3. 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 Q207 Errorless 4. 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.
$\frac{1}{2}\frac{MV^{2}}{T}$
Kerala PET 2002; EAMCET 2009 Q208 Errorless 5. Elastic and Inelastic Collision MCQ
A body of mass 2kg makes an elastic collision with another body at rest and continues to move in the original direction with one fourth of its original speed. The mass of the second body which collides with the first body is
A.
2 kg
B.
1.2 kg
C.
3 kg
D.
1.5 kg
Kerala PMT 2002; MP PET 2002; WB-JEE 2013 Q209 Errorless 6. Perfectly Inelastic Collision MCQ
A bullet of mass m moving with velocity v strikes a block of mass M at rest and gets embedded into it. The kinetic energy of the composite block will be
A.
$\frac{1}{2}mv^{2}\times\frac{m}{(m+M)}$
B.
$\frac{1}{2}mv^{2}\times\frac{M}{(m+M)}$
C.
$\frac{1}{2}mv^{2}\times\frac{(M+m)}{M}$
D.
$\frac{1}{2}Mv^{2}\times\frac{m}{(m+M)}$
IIT-JEE (Screening) 2002; DCE 2006 Q210 Errorless 8. Graphical Questions MCQ
A particle which is constrained to move along the $x$ -axis, is subjected to a force in the same direction which varies with the distance $x$ of the particle from the origin as $F(x) = -kx + ax^3$ . Here $k$ and $a$ are positive constants. For $x \geq 0$ , the functional from of the potential energy $U(x)$ of the particle is
A.
B.
C.
D.
MP PMT 2001; CBSE PMT 2004 Q211 Errorless 2. Work Done by Variable Force MCQ
A body of mass 0.1 kg moving with a velocity of 10 m/s hits a spring (fixed at the other end) of force constant 1000 N/m and comes to rest after compressing the spring. The compression of the spring is
A.
0.01 m
B.
0.1 m
C.
0.2 m
D.
0.5 m
BCECE 2001; CBSE PMT 2007; AIIMS 2008; Kerala PET 2011 Q212 Errorless 3. Conservation of Energy and Momentum MCQ
A vertical spring with force constant K is fixed on a table. A ball of mass m at a height h above the free upper end of the spring falls vertically on the spring so that the spring is compressed by a distance d. The net work done in the process is
A.
$mg(h + d) + \frac{1}{2} Kd^2$
B.
$mg(h + d) - \frac{1}{2} Kd^2$
C.
$mg(h - d) - \frac{1}{2} Kd^2$
D.
$mg(h - d) + \frac{1}{2} Kd^2$
Kerala (Engg.) 2001; EAMCET 2001; DPMT 2004; UP CPMT 2006 Q213 Errorless 4. Power MCQ
A truck of mass 30,000kg moves up an inclined plane of slope 1 in 100 at a speed of 30 kmph. The power of the truck is (Given $g = 10ms^{-2}$ )
A.
25 kW
B.
10 kW
C.
5 kW
D.
2.5 kW
UPSEAT 2001; EAMCET 2009 Q214 Errorless 5. Elastic and Inelastic Collision MCQ
A body at rest breaks up into 3 parts. If 2 parts having equal masses fly off perpendicularly each after with a velocity of $12m/s$ , then the velocity of the third part which has 3 times mass of each part is
A.
$4\sqrt{2} m/s$ at an angle of $45^{\circ}$ from each body
B.
$24\sqrt{2} m/s$ at an angle of $135^{\circ}$ from each body
C.
$6\sqrt{2} m/s$ at $135^{\circ}$ from each body
D.
$4\sqrt{2} m/s$ at $135^{\circ}$ from each body
DCE 2001, 02; Odisha JEE 2002 Q215 Errorless 5. Elastic and Inelastic Collision MCQ
A body of mass $M_{1}$ collides elastically with another mass $M_{2}$ at rest. There is maximum transfer of energy when
A.
$M_{1} > M_{2}$
B.
$M_{1} < M_{2}$
C.
$M_{1} = M_{2}$
D.
Same for all values of $M_{1}$ and $M_{2}$
UPSEAT 2000; CPMT 2002; Pb. PET 2004; MP PMT 2012 Q216 Errorless 2. Work Done by Variable Force MCQ
The potential energy of a certain spring when stretched through a distance ‘S’ is 10 joule. The amount of work (in joule) that must be done on this spring to stretch it through an additional distance ‘S’ will be
A.
30
B.
40
C.
10
D.
20
MHCET 2000; Kerala PMT 2008; AMU PMT 2009; AIPMT (Cancelled) 2015 Q217 Errorless 2. Work Done by Variable Force MCQ
Two similar springs P and Q have spring constants $K_{P}$ and $K_{Q}$ , such that $K_{P} > K_{Q}$ . They are stretched, first by the same amount (case a), then by the same force (case b). The work done by the springs $W_{P}$ and $W_{Q}$ are related as, in case (a) and case (b), respectively
A.
$W_{P} = W_{Q}; W_{P} = W_{Q}$
B.
$W_{P} > W_{Q}; W_{Q} > W_{P}$
C.
$W_{P} < W_{Q}; W_{Q} < W_{P}$
D.
$W_{P} = W_{Q}; W_{P} > W_{Q}$
DPMT 2000; Odisha JEE 2005 Q218 Errorless 5. Elastic and Inelastic Collision MCQ
A mass of 100g strikes the wall with speed 5m/s at an angle as shown in figure and it rebounds with the same speed. If the contact time is $2 \times 10^{-3}$ sec, what is the force applied on the mass by the wall
A.
$250\sqrt{3}$ N to right
B.
250 N to right
C.
$250\sqrt{3}$ N to left
D.
250 N to left
IIT-JEE 1999; UPSEAT 2003 Q219 Errorless 7. Critical Thinking MCQ
A particle free to move along the $x$ -axis has potential energy given by $U(x) = k$ $[1 - \exp (-x)^2]$ for $-\infty \leq x \leq +\infty$ , where $k$ is a positive constant of appropriate dimensions. Then
A.
At point away from the origin, the particle is in unstable equilibrium
B.
For any finite non-zero value of $x$ , there is a force directed away from the origin
C.
If its total mechanical energy is $k / 2$ , it has its minimum kinetic energy at the origin
D.
For small displacements from x=0, the motion is simple harmonic
CBSE PMT 1998; Kerala PET 2012 Q220 Errorless 1. Work Done by Constant Force MCQ
A force acts on a 30 g particle in such a way that the position of the particle as a function of time is given by $x = 3t - 4t^{2} + t^{3}$ , where x is in metres and t is in seconds. The work done during the first 4 seconds is
A.
5.28 J
B.
450 mJ
C.
490 mJ
D.
530 mJ
AIIMS 1998; UPSEAT 2000; JIPMER 2001; Kerala PMT 2004 Q221 Errorless 3. 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 Q222 Errorless 3. 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 Q223 Errorless 3. 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; JIPMER 2001, 02; BHU 2005; AFMC 2005 Q224 Errorless 6. 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 Q225 Errorless 1. 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°