UPSC Physics Work, Energy And Power / कार्य, ऊर्जा एवं शक्ति Question Bank

done Laws of Motion, Force, Work, Energy and Power, Centre of Mass Total Questions - 60

• question_answer1)
  The working principle of a washing machine is:                                [IAS Prelim]                           
  A)
                         centrifugation done clear
  B)
       dialysis done clear
  C)
  reverse osmosis   done clear
  D)
                   diffusion done clear
  View Solution play_arrow

• question_answer2)
  Newton's laws of motion do not hold good for objects
  A)
  at rest            done clear
  B)
  moving slowly done clear
  C)
  moving with high velocity done clear
  D)
  moving with velocity comparable to velocity  of light done clear
  View Solution play_arrow

• question_answer3)
        A jet engine works on the principle of conservation of                                   [NDA]
  A)
  linear momentum done clear
  B)
      angular momentum done clear
  C)
  energy           done clear
  D)
  mass done clear
  View Solution play_arrow

• question_answer4)
        Which one among the following is correct for resultant of balanced forces?                              [NDA]
  A)
  It is zero     done clear
  B)
       It is non-zero done clear
  C)
  It varies continuously done clear
  D)
  None of the above done clear
  View Solution play_arrow

• question_answer5)
        When a moving bus suddenly applies brakes, the passengers sitting in it fall in the forward direction. This can be explained by                                    [NDA]
  A)
  the theory of relativity done clear
  B)
  Newton?s first law done clear
  C)
  Newton?s second law done clear
  D)
  Newton?s third law done clear
  View Solution play_arrow

• question_answer6)
        A book is kept on the surface of a table. If the gravitational pull of the earth on the book is the force of action, then the force of reaction is exerted by                               [NDA]
  A)
  the book on the table done clear
  B)
  the book on the earth done clear
  C)
  the table on the book done clear
  D)
  the table on the earth done clear
  View Solution play_arrow

• question_answer7)
        The pressure exerted on the ground by a man is greatest                               [CDS]
  A)
  when the lies down in the ground done clear
  B)
  when the stands on the toes of one foot done clear
  C)
  when the stands with both foot flat on the ground done clear
  D)
  all of the above yield the same pressure done clear
  View Solution play_arrow

• question_answer8)
        If a ship moves from freshwater into seawater, it will                                    [CDS]
  A)
  sink completely   done clear
  B)
       sink a little bit done clear
  C)
  rise a little higher done clear
  D)
       remain unaffected done clear
  View Solution play_arrow

• question_answer9)
  A man is at rest in the middle of a horizontal plane of perfectly smooth surface of ice. He can move himself to the shore by making use of Newton's [NDA]
  A)
  first law of motion done clear
  B)
  second law of motion done clear
  C)
  third law of motion done clear
  D)
  first, second and third laws of motion done clear
  View Solution play_arrow

• question_answer10)
        If an object having mass of 1 kg is subjected to a force of 1 N it moves with                           [CDS]
  A)
  a speed of 1 m/s done clear
  B)
  a speed of 1 km/s done clear
  C)
  an acceleration of \[10\,m/{{s}^{2}}\] done clear
  D)
  an acceleration of \[1\,m/{{s}^{2}}\] done clear
  View Solution play_arrow

• question_answer11)
  An athlete diving off a high springboard can perform a variety of exercises in the air before entering the water below. Which one of the following parameters will remain constant during the fall? [CDS]
  A)
  The athlete's linear momentum done clear
  B)
  The athlete's moment of inertia done clear
  C)
  The athlete's kinetic energy done clear
  D)
  The athlete's angular momentum done clear
  View Solution play_arrow

• question_answer12)
       

  Statement A: While drawing a line on a paper, friction force acts on paper in the same direction along which line is drawn on the paper.

  Statement B: Friction always opposes motion.

  A)
  Statement A is correct. done clear
  B)
  Statement B is correct. done clear
  C)
  Both statements are correct. done clear
  D)
  Both statements are incorrect. done clear
  View Solution play_arrow

• question_answer13)
       

  Assertion [A]: A man standing on a completely frictionless surface can propel himself by whistling.

  Reason [R]: If no external force acts on a system, its momentum cannot change.                    [IAS Prelim]

  A)
  Both A and R are true and R is the correct explanation of A done clear
  B)
  Both A and R are true but R is not a correct explanation of A done clear
  C)
  A is true but R is false done clear
  D)
  A is false but R is true done clear
  View Solution play_arrow

• question_answer14)
        A spherical body moves with a uniform angular velocity (w) around a circular path of radius r. Which one of the following statements is correct?                               [IAS Prelim]
  A)
  The body has no acceleration done clear
  B)
  The body has a radial acceleration \[{{\omega }^{2}}r\] directed toward centre of path done clear
  C)
  The body has a radial acceleration \[2/5{{\omega }^{2}}r\] directed away from the centre of the path done clear
  D)
  The body has an acceleration \[{{\omega }^{2}}\] tangential to its path done clear
  View Solution play_arrow

• question_answer15)
        On the basis of following features identify the correct option.

  A. It is measured in units of kg m/s.

  B. Its direction is same as that of velocity of body.

  A)
  Momentum       done clear
  B)
       Inertia done clear
  C)
  Both A and B     done clear
  D)
       Neither A and B done clear
  View Solution play_arrow

• question_answer16)
        Ball bearings are used in bicycles, cars, etc., because                                   [IAS Prelim]
  A)
  the actual area of contact between the wheel and axle is increased done clear
  B)
  the effective area of contact between the wheel and axle is increased done clear
  C)
  the effective area of contact between the wheel and axle is reduced done clear
  D)
  None of the above statements is correct done clear
  View Solution play_arrow

• question_answer17)
  In cricket match, while catching a fast moving ball, a fielder in the ground gradually pulls his hands backwards with the moving ball to reduce the velocity to zero. The act represents [CDS]
  A)
  Newton's first law of motion done clear
  B)
  Newton's second law of motion done clear
  C)
  Newton's third law of motion done clear
  D)
  Law of conservation of energy done clear
  View Solution play_arrow

• question_answer18)
       

  Statement A: Pulling a lawn roller is easier than pushing it.

  Statement B: Pushing increases the apparent weight and hence the force of friction.                    [CDS]

  A)
  Statement A is correct. done clear
  B)
  Statement B is correct. done clear
  C)
  Both statements are correct.  done clear
  D)
  Both statements are incorrect. done clear
  View Solution play_arrow

• question_answer19)
        It is difficult to cut things with a blunt knife because                                     [CDS]
  A)
  the pressure exerted by knife for a given force increases with increase in bluntness done clear
  B)
  a sharp edge decreases the pressure exerted by knife for a given force done clear
  C)
  a blunt knife decreases the pressure for a given force done clear
  D)
  a blunt knife decreases the area of intersection done clear
  View Solution play_arrow

• question_answer20)
       

  Statement A: When a gun is fired it recoils, i.e., it pushes back, with much less velocity than the velocity of the bullet.

  Statement B: Velocity of the recoiling gun is less because the gun is much heavier than the bullet.                               [CDS]

  A)
  Statement A is correct. done clear
  B)
  Statement B is correct. done clear
  C)
  Both statements are correct. done clear
  D)
  Both statements are incorrect. done clear
  View Solution play_arrow

• question_answer21)
        Two teams are pulling a rope with equal and opposite forces each of 5 kN in a tug of war so that a condition of equilibrium exists. What will be the tensile force in the rope?                              [NDA]
  A)
  Zero                  done clear
  B)
       2.5 kN done clear
  C)
  5 kN          done clear
  D)
       10 kN done clear
  View Solution play_arrow

• question_answer22)
       

  	Column-I
  A.	Rocket propulsion	P.	Force
  B.	Agent which causes Acceleration	Q.	Momentum
  C.	Product of mass and Velocity	R.	S.I. unit of force
  D.	Newton	S.	Law of Conservation momentum

   
  A)
  A\[\to \]S;   B\[\to \]P;   C\[\to \]R;   D\[\to \]Q done clear
  B)
  A\[\to \]P;   B\[\to \]S;   C\[\to \]R;   D\[\to \]Q done clear
  C)
  A\[\to \]S;   B\[\to \]P;   C\[\to \]Q;   D\[\to \]R done clear
  D)
  A\[\to \]P;   B\[\to \]S;   C\[\to \]Q;   D\[\to \]R done clear
  View Solution play_arrow

• question_answer23)
       

  Statement A: While walking on ice, one should take small steps to avoid slipping.

  Statement B: This is because smaller steps ensure smaller friction.

  A)
  Statement A is correct. done clear
  B)
  Statement B is correct. done clear
  C)
  Both statements are correct. done clear
  D)
  Both statements are incorrect. done clear
  View Solution play_arrow

• question_answer24)
  Thomas and Mary are playing carom board. They arrange the seeds in the vertical order. Thomas strikes on the seeds with the striker, with a great speed. He finds that, the stakes do not fall down. On the other hand, when he strikes the seeds with less speed, all the seeds of the stakes fell down. Which property of force this shows?
  A)
  Newton's third law                      done clear
  B)
  Motion done clear
  C)
  Inertia        done clear
  D)
  Reaction of force done clear
  View Solution play_arrow

• question_answer25)
        A man getting down a running bus, falls forward because.
  A)
  due to inertia of rest, road is left behind and man reaches forward done clear
  B)
  due to inertia of motion upper part of body continues to be in motion in forward direction while feet come to rest as soon as they touch the road done clear
  C)
  he leans forward as a matter of habit done clear
  D)
  of the combined effect of all the three factors stated in [a], [b] and [c] done clear
  View Solution play_arrow

• question_answer26)
        The work done becomes zero if
  A)
  force perpendicular to the displacement done clear
  B)
  displacement is zero done clear
  C)
  force acting on the body is zero done clear
  D)
  All of the above done clear
  View Solution play_arrow

• question_answer27)
        When an incandescent electric bulb glows                           [CDS]
  A)
  the electric energy is completely converted into light done clear
  B)
  the electric energy is partly converted into light energy and partly into heat energy done clear
  C)
  the light energy is converted into electric energy done clear
  D)
  the electric energy is converted into magnetic energy done clear
  View Solution play_arrow

• question_answer28)
        The sum of the change in kinetic and potential energy is always                                [SSC CGL]
  A)
  Zero          done clear
  B)
       Positive done clear
  C)
  Negative        done clear
  D)
       None of the above done clear
  View Solution play_arrow

• question_answer29)
        The potential energy is always the same for an object with the same
  A)
  Velocity         done clear
  B)
       Speed done clear
  C)
  Acceleration     done clear
  D)
       Position done clear
  View Solution play_arrow

• question_answer30)
        If velocity of a body is twice of previous velocity, then kinetic energy will become                                [NDA]
  A)
  2 times              done clear
  B)
       1/2 times done clear
  C)
  4 times              done clear
  D)
       1 times done clear
  View Solution play_arrow

• question_answer31)
        In case of negative work the angle between the force and displacement is
  A)
  \[0{}^\circ \]                 done clear
  B)
       \[45{}^\circ \] done clear
  C)
  \[90{}^\circ \]               done clear
  D)
       \[180{}^\circ \]  done clear
  View Solution play_arrow

• question_answer32)
        How much time will it take to perform 440 J of work at a rate of 11 W?
  A)
  50 s                              done clear
  B)
  40 s done clear
  C)
  30 s                  done clear
  D)
       20 s done clear
  View Solution play_arrow

• question_answer33)
        When a stone tied to a string is whirled in a circle, the work done on it by the string is
  A)
  positive              done clear
  B)
       negative done clear
  C)
  zero           done clear
  D)
       undefined done clear
  View Solution play_arrow

• question_answer34)
  Match the Column I and Column II.

  	Column-I
  A.	Electric motor	P.	Electrical energy  to sound energy
  B.	Electric bell	Q.	Electrical energy to mechanical  energy
  C.	Electric bulb electrical	R.	Light energy to Energy
  D.	Photoelectric  mechanical	S.	Heat energy to cell energy
  E.	Steam engine light Energy	T.	Electric energy to

  A)
  A-P;   B-Q;   C-T;   D-R;   E-S done clear
  B)
  A-Q;   B-P;   C-T;   D-T;   E-S done clear
  C)
  A-Q;   B-P;   C-T;   D-S;   E-R done clear
  D)
  A-Q;   B-P;   C-T;   D-R;   E-S done clear
  View Solution play_arrow

• question_answer35)
        Which one of the following physical quantities is represented by the shaded area in the given graph?
  A)
  Torque              done clear
  B)
       Impulse done clear
  C)
  Power                done clear
  D)
       Work done done clear
  View Solution play_arrow

• question_answer36)
        Two masses m and 9 m are moving with equal kinetic energies. The ratio of the magnitudes of their momenta is
  A)
  1 : 1                  done clear
  B)
       1 : 3 done clear
  C)
  3 : 1                  done clear
  D)
       1 : 9 done clear
  View Solution play_arrow

• question_answer37)
        A particle oscillates in one dimension about the equilibrium position subject to a force \[{{F}_{xx}}(x)\] that has an associated potential energy U(x). If k is the force constant, which one of the following relations is true?                              [NDA]
  A)
  \[{{F}_{x}}(x)=k{{x}^{2}}\]   done clear
  B)
       \[{{F}_{x}}(x)=kx\] done clear
  C)
  \[U(x)=\frac{1}{2}kx\]     done clear
  D)
       \[U(x)=\frac{1}{2}{{k}^{2}}x\] done clear
  View Solution play_arrow

• question_answer38)
        If a light body and a heavy body have equal momentum, then                                 [NDA]
  A)
  the lighter body has greater energy than the heavier body done clear
  B)
  the lighter body has lesser kinetic energy than the heavier body done clear
  C)
  the kinetic energy of the lighter body is equal to the kinetic energy of the heavier body done clear
  D)
  the kinetic energy of both the bodies are independent of momentum. done clear
  View Solution play_arrow

• question_answer39)
        A rubber ball dropped from 24 m height loses its kinetic energy by 25%. What is the height to which it rebounds.
  A)
  6m  done clear
  B)
                               12m done clear
  C)
  18m            done clear
  D)
       24m done clear
  View Solution play_arrow

• question_answer40)
        The potential energy of a freely falling object decreases progressively.
  A)
  The law of conservation of energy is violated done clear
  B)
  Potential energy gets converted into kinetic energy progressively done clear
  C)
  Sum of Potential Energy and Kinetic Energy at any point during the free fall remains constant done clear
  D)
  Both [b] and [c] done clear
  View Solution play_arrow

• question_answer41)
        In which of the following examples, work done is negative?
  A)
  Work done by the force of gravity on a moving aeroplane done clear
  B)
  Work done by the force of gravity on a ball thrown upwards done clear
  C)
  Work done by the force of gravity on a freely falling object done clear
  D)
  Work done by the force of gravity on a satellite done clear
  View Solution play_arrow

• question_answer42)
       

  Assertion: A man gets completely exhausted in trying to push a stationary wall.

  Reason: Work done by the man on the wall is zero.

  A)
  If both Assertion and Reason are correct and Reason is the correct explanation of Assertion. done clear
  B)
  If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion. done clear
  C)
  If Assertion is correct but Reason is incorrect. done clear
  D)
  If Assertion is incorrect but Reason is correct. done clear
  View Solution play_arrow

• question_answer43)
        A boy has four options to move a body through 3m as indicated. In which case is maximum work done?
  A)
  Push over an inclined plane done clear
  B)
  Lift vertically upwards done clear
  C)
  Push over smooth rollers done clear
  D)
  Push on a plane horizontal surface done clear
  View Solution play_arrow

• question_answer44)
        An electrical appliance of 500 W is used for 5 hours per day. Energy consumed in 30 days will be
  A)
  2.5 kWh done clear
  B)
                   25 kWh done clear
  C)
  75 kWh     done clear
  D)
       None of these done clear
  View Solution play_arrow

• question_answer45)
        Two persons do the same amount of work, one in 10 s and the other in 20 s. Find the ratio of the power used by the first person to that by the second person.
  A)
  6 : 4                  done clear
  B)
       2 : 1 done clear
  C)
  5 : 2                  done clear
  D)
       4 : 3 done clear
  View Solution play_arrow

• question_answer46)
        Rahul takes I minute to raise a box to a height of 1 metre and Rohan takes 1/2 minute to do so. Comment on the energy by the two.
  A)
  Energy spent by the Rahul is more. done clear
  B)
  Energy spent by both Rahul and Rohan is same. done clear
  C)
  Energy spent by the Rohan is more done clear
  D)
  Cannot be said done clear
  View Solution play_arrow

• question_answer47)
        Gravitational potential energy of an object will
  A)
  increase by increasing the path along which the object is moved done clear
  B)
  decrease by increasing the path along w4iich the object is moved done clear
  C)
  not effected by changing the path, provided the overall height is same done clear
  D)
  None of these done clear
  View Solution play_arrow

• question_answer48)
        When you compress a coil spring you do work on it. The elastic potential energy
  A)
  increases   done clear
  B)
       decreases done clear
  C)
  disappears       done clear
  D)
       remains the same done clear
  View Solution play_arrow

• question_answer49)
        No work is done when
  A)
  a nail is plugged into a wooden board done clear
  B)
  a box is pushed along a horizontal floor done clear
  C)
  there is no component of force parallel to the direction of motion done clear
  D)
  there is no component of force normal to the direction of force done clear
  View Solution play_arrow

• question_answer50)
        Two identical particles move towards each other with velocity 2v and v respectively. The velocity of centre of mass is
  A)
  v                      done clear
  B)
       v/3 done clear
  C)
  v/2                    done clear
  D)
       zero done clear
  View Solution play_arrow

• question_answer51)
        A solid sphere is rotating in free space. If the radius of the sphere is increased keeping mass same which one of the following will not be affected?
  A)
  Angular velocity done clear
  B)
  Angular momentum done clear
  C)
  Moment of inertia done clear
  D)
  Rotational kinetic energy done clear
  View Solution play_arrow

• question_answer52)
        A couple is acting on a two particle systems. The resultant motion will be
  A)
  purely rotational motion done clear
  B)
  purely linear motion done clear
  C)
  both a and b done clear
  D)
  neither of a and b done clear
  View Solution play_arrow

• question_answer53)
        A simple machine helps a person in doing:                                      [IAS Prelim]
  A)
  less work done clear
  B)
  the same amount of work with lesser force done clear
  C)
  the same amount of work slowly done clear
  D)
  the same amount of work much faster done clear
  View Solution play_arrow

• question_answer54)
  The wide handle of screw is based upon
  A)
  Newton's second law of motion done clear
  B)
  law of conservation of linear momentum done clear
  C)
  turning moment of force done clear
  D)
  None of these done clear
  View Solution play_arrow

• question_answer55)
        For a particle revolving in a circular path, the acceleration of the particle is                             [NDA]
  A)
  along the tangent done clear
  B)
  along the radius done clear
  C)
  zero done clear
  D)
  along the circumference of the circle done clear
  View Solution play_arrow

• question_answer56)
        A fan is moving around its axis, What will be its motion regarded as?
  A)
  Pure rolling done clear
  B)
  Rolling with shipping done clear
  C)
  Skidding done clear
  D)
  Pure rotation done clear
  View Solution play_arrow

• question_answer57)
        A composite disc is to be made using equal masses of aluminium and iron so that it has as high a moment of inertia as possible. This is possible when
  A)
  the surfaces of the disc are made of iron with aluminium inside done clear
  B)
  the whole of aluminium is kept in the core and the iron at the outer rim of the disc done clear
  C)
  the whole of the iron is kept in the core and the aluminium at the outer rim of the disc done clear
  D)
  the whole disc is made with thin alternate sheets of iron and aluminium done clear
  View Solution play_arrow

• question_answer58)
        During summersault, a swimmer bends his body to
  A)
  increase moment of Inertia done clear
  B)
  decrease moment of Inertia done clear
  C)
  decrease the angular momentum done clear
  D)
  reduce the angular velocity done clear
  View Solution play_arrow

• question_answer59)
        For a given mass and size, moment of inertia of a solid disc is
  A)
  more than that of a ring done clear
  B)
  less than that of a ring done clear
  C)
  equal to that of a ring done clear
  D)
  depend on the material of ring and disc done clear
  View Solution play_arrow

• question_answer60)
        A gymnast takes turns with her arms & legs stretched. When she pulls her arms and legs                                   [CDS]
  A)
  the angular velocity decreases done clear
  B)
  the moment of inertia decreases done clear
  C)
  the angular velocity stays constant done clear
  D)
  the angular momentum increases done clear
  View Solution play_arrow