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Work Power and Energy

505 Questions Start Allen Test
All Exams Allen Objective Errorless
Q326 Allen KINETIC ENERGY & WORK ENERGY THEOREM MCQ
If the momentum of a body increases by 2% then it's kinetic energy :-
A.
increases by 2%
B.
increases by 4%
C.
increases by 8%
D.
increases by 16%
Q327 Allen KINETIC ENERGY & WORK ENERGY THEOREM MCQ
The graph between $\sqrt{\mathrm{E_k}}$ and $\frac{1}{p}$ is $(\mathrm{E_K} =$ kinetic energy and $p =$ momentum) -
A.
B.
C.
D.
Q328 Allen KINETIC ENERGY & WORK ENERGY THEOREM MCQ
The graph between kinetic energy $E_{K}$ and velocity V is ā€“
A.
B.
C.
D.
Q329 Allen KINETIC ENERGY & WORK ENERGY THEOREM MCQ
A constant force F is applied to a body of mass m moving with initial velocity u. If after the body undergoes a displacement S, its velocity becomes v, then the total work done is:
A.
$m[v^{2} + u^{2}]$
B.
$\frac{m}{2}[u^{2} + v^{2}]$
C.
$\frac{m}{2}[v^{2} - u^{2}]$
D.
$m[v^{2} - u^{2}]$
Q330 Allen KINETIC ENERGY & WORK ENERGY THEOREM MCQ
A body of mass 6 kg is acted upon by a force which causes displacement in it given as $S = \frac{t^{3}}{4}$ metres where 't' is time. The work done by the force in 2 seconds is:
A.
18 J
B.
9 J
C.
27 J
D.
16 J
Q331 Allen KINETIC ENERGY & WORK ENERGY THEOREM MCQ
A force acts on a 20 g particle in such a way that the position of the particle as a function of time is given by $x = 2t - 3t^{2} + 2t^{3}$ , where x is in metre and t is in second. The work done during the first 3 seconds is:
A.
5.28 J
B.
28.8 J
C.
14.4 J
D.
7.2 J
Q332 Allen KINETIC ENERGY & WORK ENERGY THEOREM MCQ
A ball of mass 1 kg and another of mass 3 kg 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.
1:3
B.
1:2
C.
$1:\sqrt{3}$
D.
$\sqrt{3}:1$
Q333 Allen KINETIC ENERGY & WORK ENERGY THEOREM MCQ
A 2 kg ball is thrown up with an initial speed 16 m/s and reaches a maximum height of 10 m. How much energy is dissipated by air drag acting on the ball during the ascent?
A.
40 J
B.
56 J
C.
36 J
D.
72 J
Q334 Allen KINETIC ENERGY & WORK ENERGY THEOREM MCQ
Three particles A, B and C are projected from the top of a tower with the same speed. A is thrown straight upwards, B straight down and C horizontally. They hit the ground with speeds $V_{A}$ , $V_{B}$ and $V_{C}$ then:
A.
$V_{A} = V_{B} > V_{C}$
B.
$V_{A} = V_{B} = V_{C}$
C.
$V_{A} > V_{B} = V_{C}$
D.
$V_{B} > V_{C} > V_{A}$
Q335 Allen KINETIC ENERGY & WORK ENERGY THEOREM MCQ
Velocity-time graph of a particle of mass 2 kg moving in a straight line is as shown in figure. Work done by all the forces acting on the particle is :
A.
100 J
B.
-100 J
C.
-200 J
D.
200 J
Q336 Allen CONSERVATIVE FORCE & POTENTIAL ENERGY MCQ
Which of the following statements is not true for work done by conservative forces:-
A.
It does not depend on path
B.
It is equal to the difference of initial and final potential energy function
C.
It can be recovered completely
D.
None of the above
Q337 Allen CONSERVATIVE FORCE & POTENTIAL ENERGY MCQ
Which of the following statement is incorrect for a conservative field?
A.
Work done in going from initial to final position is equal to change in kinetic energy of the particle.
B.
Work done depends on path but not on initial and final positions.
C.
Work done does not depend on path but depends only on initial and final positions
D.
Work done on a particle in the field for a round trip is zero.
Q338 Allen CONSERVATIVE FORCE & POTENTIAL ENERGY MCQ
As shown in the diagram a particle is to be carried from point A to C via paths (I), (II) and (III) in gravitational field, then which of the following statements is correct:
A.
Work done is same for all the paths
B.
Work done is minimum for path (II)
C.
Work done is maximum for path (I)
D.
None of the above
Q339 Allen CONSERVATIVE FORCE & POTENTIAL ENERGY MCQ
Which of the following is a non conservative force :-
A.
Electric force
B.
Gravitational force
C.
Spring force
D.
Viscous force
Q340 Allen CONSERVATIVE FORCE & POTENTIAL ENERGY MCQ
The relation between conservative force and potential energy U is given by:
A.
$F = \frac{dU}{dx}$
B.
$F = \int U dx$
C.
$F = -\frac{dU}{dx}$
D.
$F = \frac{dU}{dx}$
Q341 Allen CONSERVATIVE FORCE & POTENTIAL ENERGY MCQ
A 10 kg satellite completes one revolution around the earth at a height of 100 km in 108 minutes. The work done by the gravitational force of earth will be -
A.
$108 \times 100 \times 10$ J
B.
$\frac{108 \times 10}{100}$ J
C.
0 J
D.
$\frac{100 \times 10}{108}$ J
Q342 Allen CONSERVATIVE FORCE & POTENTIAL ENERGY MCQ
For the path PQR in a conservative force field the amount of work done in carrying a body from P to Q and from Q to R are 15 Joule and 5 Joule respectively. The work done in carrying the body from P to R will be ā€“
A.
20 J
B.
10 J
C.
5 J
D.
Zero
Q343 Allen CONSERVATIVE FORCE & POTENTIAL ENERGY MCQ
A particle is moved from (0, 0) to (a, a) under a force $\vec{\mathrm{F}} = (3\hat{\mathrm{i}} + 4\hat{\mathrm{j}})$ from two paths. Path 1 is OP and path 2 is OQP. Let $W_{1}$ and $W_{2}$ be the work done by this force in these two paths. Then :
A.
$W_{1} = W_{2}$
B.
$W_{1} = 2W_{2}$
C.
$W_{2} = 2W_{1}$
D.
$W_{2} = 4W_{1}$
Q344 Allen CONSERVATIVE FORCE & POTENTIAL ENERGY MCQ
A body of mass 3 kg falls from a height of 20 m. What is the loss in potential energy :-
A.
400 J
B.
300 J
C.
200 J
D.
600 J
Q345 Allen CONSERVATIVE FORCE & POTENTIAL ENERGY MCQ
The mass of a bucket full of water is 13 kg. It is being pulled up from a 10 m deep well. Due to a hole in the bucket 4 kg water flows out of the bucket. The work done in drawing the bucket out of the well will be $(g = 10m/s^{2})-$
A.
900 J
B.
1300 J
C.
1100 J
D.
1700 J
Q346 Allen CONSERVATIVE FORCE & POTENTIAL ENERGY MCQ
A uniform chain of length L and mass M is lying on a smooth table and $\frac{1}{3}$ rd of its length is hanging down from the edge of the table. If g is the acceleration due to gravity, the work done to pull the hanging part on the table is :-
A.
MgL
B.
$\frac{MgL}{18}$
C.
$\frac{MgL}{9}$
D.
$\frac{2MgL}{9}$
Q347 Allen CONSERVATIVE FORCE & POTENTIAL ENERGY MCQ
A brick has 3 sides a, b, c {a > b > c}. The brick can be kept on ground on any face. The work required to be done to move slowly from minimum potential energy situation to maximum potential energy situation of brick is :
A.
$\mathrm{mg}\left(\frac{\mathrm{a}}{2} -\frac{\mathrm{b}}{2}\right)$
B.
$\mathrm{mg}\left(\frac{\mathrm{a}}{2} -\frac{\mathrm{c}}{2}\right)$
C.
$\mathrm{mg}\left(\frac{\mathrm{b}}{2} -\frac{\mathrm{c}}{2}\right)$
D.
$\mathrm{mg}\left(\frac{\mathrm{a} + \mathrm{c}}{2} -\frac{\mathrm{b}}{2}\right)$
Q348 Allen CONSERVATIVE FORCE & POTENTIAL ENERGY MCQ
If a spring extends by x on loading then energy stored in the spring is :- (T is tension in the spring, K = spring constant)
A.
$\frac{T^{2}}{2x}$
B.
$\frac{T^{2}}{2K}$
C.
$\frac{2K}{T^{2}}$
D.
$\frac{2T^{2}}{K}$
Q349 Allen CONSERVATIVE FORCE & POTENTIAL ENERGY MCQ
A spring of force constant 1000 N/m has an extension of 15 cm. The work done in extending it from 15 cm to 25 cm is:-
A.
16 J
B.
8 J
C.
32 J
D.
20 J
Q350 Allen CONSERVATIVE FORCE & POTENTIAL ENERGY MCQ
In stretching a spring by 5 cm energy stored is given by U, then the energy stored if the spring is stretched by 10 cm will be :-
A.
U
B.
5U
C.
4U
D.
25U