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Work, Power & Energy

769 Questions Start Allen Test
All Exams Allen Advance Errorless
Kerala PET 2002; EAMCET 2009 Q301 Errorless 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 Q302 Errorless 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 Q303 Errorless 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.
IIT-JEE 2002 Q304 Advance ARCHIVE: JEE ADVANCED MCQ
A particle, which is constrained to move along 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 constant. For $x \geq 0$ , the functional form of the potential energy $U(x)$ of the particle is
A.
B.
C.
$U(x)$
D.
$U(x)$
MP PMT 2001; CBSE PMT 2004 Q305 Errorless 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 Q306 Errorless 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 Q307 Errorless 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 Q308 Errorless 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 Q309 Errorless 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 Q310 Errorless 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 Q311 Errorless 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 Q312 Errorless 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
2000 Q313 Advance SINGLE CORRECT CHOICE TYPE QUESTIONS MCQ
A dam is situated at a height of 550 metre above sea level and supplies water to a power house which is at a height of 50 metre above sea level. 2000 kg of water passes through the turbines per second. The maximum electrical power output of the power house if the whole system were 80% efficient is
A.
8 MW
B.
10 MW
C.
12.5 MW
D.
16 MW
IIT-JEE 2000 Q314 Advance ARCHIVE: JEE ADVANCED MCQ
A wind-powered generator converts wind energy into electrical energy. Assume that the generator converts a fixed fraction of wind energy interception by its blades into electrical energy. For wind speed v, the electrical power output will be proportional to
A.
$v$
B.
$v^{2}$
C.
$v^{3}$
D.
$v^{4}$
IIT-JEE 1999; UPSEAT 2003 Q315 Errorless 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
IIT-JEE 1999 Q316 Advance ARCHIVE: JEE ADVANCED MCQ
A spring of force constant k is cut into two pieces such that one piece is double the length of the other. Then the long piece will have a force constant of
A.
$\left(\frac{2}{3}\right)k$
B.
$\left(\frac{3}{2}\right)k$
C.
3k
D.
6k
CBSE PMT 1998; Kerala PET 2012 Q317 Errorless 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 Q318 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 Q319 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 Q320 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; JIPMER 2001, 02; BHU 2005; AFMC 2005 Q321 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
IIT-JEE 1998 Q322 Advance ARCHIVE: JEE ADVANCED MCQ
A stone tied to a string of length L is whirled in a vertical circle with the other end of the string at the centre. At a certain instant of time, the stone is at the lowest position and has a speed u. The magnitude of the change in velocity as it reaches a position where the string is horizontal is
A.
$\sqrt{u^{2}-2gL}$
B.
$\sqrt{2gL}$
C.
$\sqrt{u^{2}-gL}$
D.
$\sqrt{2(u^{2}-gL)}$
IIT-JEE 1998 Q323 Advance ARCHIVE: JEE ADVANCED MCQ
A force $\vec{F} = -k(y\hat{i} + x\hat{j})$ , where $k$ is a positive constant, acts on a particle moving in the $xy$ plane. Starting from the origin, the particle is taken along the positive $x$ -axis to the point $(a,0)$ , and then parallel to the $y$ -axis to the point $(a,a)$ . The total work done by the force on the particle is
A.
$-2ka^{2}$
B.
$2ka^{2}$
C.
$-ka^{2}$
D.
$ka^{2}$
JIPMER 1997; CBSE PMT 1999; BHU 2000; RPMT 2000; Odisha JEE 2002 Q324 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°
BHU 1997; MP PET 2000; CBSE PMT 2000; MH CET 2000; JIPMER 2001, 02; AMU (Med.) 2002; DPMT 2003 Q325 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