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Work Power and Energy

267 Questions Start Errorless Test
All Exams Allen Objective Errorless
AIEEE 2004; BHU 2006 Q176 Errorless 4. 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.
$\frac{mv_{1}^{2}t}{t_{1}^{2}}$
Kerala PMT 2004 Q177 Errorless 4. Power MCQ
Power of a water pump is 2 kW. If $g = 10 \, m/sec^{2}$ , the amount of water it can raise in one minute to a height of 10 m is
A.
2000 litre
B.
1000 litre
C.
100 litre
D.
1200 litre
Odisha PMT 2004 Q178 Errorless 5. Elastic and Inelastic Collision MCQ
A shell initially at rest explodes into two pieces of equal mass, then the two pieces will
A.
Be at rest
B.
Move with different velocities in different directions
C.
Move with the same velocity in opposite directions
D.
Move with the same velocity in same direction
DCE 2004 Q179 Errorless 5. Elastic and Inelastic Collision MCQ
Two balls at same temperature collide. What is conserved
A.
Temperature
B.
Velocity
C.
Kinetic energy
D.
Momentum
Odisha PMT 2004 Q180 Errorless 5. Elastic and Inelastic Collision MCQ
A body of mass m is at rest. Another body of same mass moving with velocity V makes head on elastic collision with the first body. After collision the first body starts to move with velocity
A.
V
B.
2V
C.
Remain at rest
D.
No predictable
UPSEAT 2004 Q181 Errorless 5. 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
BCECE 2004; J & K CET 2006 Q182 Errorless 5. 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
UPSEAT 2004 Q183 Errorless 7. Critical Thinking MCQ
Consider elastic collision of a particle of mass m moving with a velocity u with another particle of the same mass at rest. After the collision the projectile and the struck particle move in directions making angles $\theta_{1}$ and $\theta_{2}$ respectively with the initial direction of motion. The sum of the angles. $\theta_{1} + \theta_{2}$ , is
A.
$45^{\circ}$
B.
$90^{\circ}$
C.
$135^{\circ}$
D.
$180^{\circ}$
IIT-JEE (Screening) 2004; J & K CET 2006 Q184 Errorless 8. 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.
MP PET 2003 Q185 Errorless 1. 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
BCECE 2003 Q186 Errorless 2. Work Done by Variable Force MCQ
A spring when stretched by 2 mm its potential energy becomes 4 J. If it is stretched by 10 mm, its potential energy is equal to
A.
4 J
B.
54 J
C.
415 J
D.
None
CBSE PMT 2003; KCET 2012 Q187 Errorless 3. 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.
$m_{2}/m_{1}$
MP PET 2003 Q188 Errorless 3. 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.
$a^0$
Pb. PET 2003 Q189 Errorless 4. Power MCQ
From an automatic gun a man fires 360 bullet per minute with a speed of 360 km/hour. If each weighs 20 g, the power of the gun is
A.
600 W
B.
300 W
C.
150 W
D.
75 W
EAMCET 2003 Q190 Errorless 5. Elastic and Inelastic Collision MCQ
Two particles having position vectors $\vec{r}_1 = (3\hat{i} + 5\hat{j})$ metres and $\vec{r}_2 = (-5\hat{i} - 3\hat{j})$ metres are moving with velocities $\vec{v}_1 = (4\hat{i} + 3\hat{j})m / s$ and $\vec{v}_2 = (\alpha \hat{i} + 7\hat{j}) m / s$ . If they collide after 2 seconds, the value of ' $\alpha'$ is
A.
2
B.
4
C.
6
D.
8
Pb. PET 2003 Q191 Errorless 6. Perfectly Inelastic Collision MCQ
Two bodies of masses 0.1 kg and 0.4 kg move towards each other with the velocities 1 m/s and 0.1 m/s respectively, After collision they stick together. In 10 sec the combined mass travels
A.
120 m
B.
0.12 m
C.
12 m
D.
1.2 m
IIT-JEE (Screening) 2003 Q192 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 Q193 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 Q194 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
AFMC 2002 Q195 Errorless 1. Work Done by Constant Force MCQ
If force and displacement of particle in direction of force are doubled. Work would be
A.
Double
B.
4 times
C.
Half
D.
$1 / 4$ times
AFMC 2002 Q196 Errorless 1. Work Done by Constant Force MCQ
Which of the following is a unit of energy
A.
Unit
B.
Watt
C.
Horse Power
D.
None
JIPMER 2002 Q197 Errorless 1. Work Done by Constant Force MCQ
A 50kg man with 20kg load on his head climbs up 20 steps of 0.25m height each. The work done in climbing is
A.
5 J
B.
350 J
C.
100 J
D.
3430 J
DCE 2002; Odisha JEE 2005; Kerala PMT 2006; Kerala PET 2008 Q198 Errorless 2. Work Done by Variable Force MCQ
A particle moves under the effect of a force $F = Cx$ from $x = 0$ to $x = x_{1}$ . The work done in the process is
A.
$Cx_{1}^{2}$
B.
$\frac{1}{2}Cx_{1}^{2}$
C.
$Cx_{1}$
D.
Zero
Odisha JEE 2002; Kerala PMT 2006 Q199 Errorless 2. Work Done by Variable Force MCQ
A position dependent force $F=7-2x+3x^{2}$ newton acts on a small body of mass 2 kg and displaces it from x=0 to x=5m. The work done in joules is
A.
70
B.
270
C.
35
D.
135
Odisha JEE 2002 Q200 Errorless 2. Work Done by Variable Force MCQ
When a spring is stretched by 2 cm, it stores 100 J of energy. If it is stretched further by 2 cm, the stored energy will be increased by
A.
100 J
B.
200 J
C.
300 J
D.
400 J