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CBSE Questions for Class 11 Medical Physics Work, Energy And Power Quiz 13 - MCQExams.com

A body of mass 10 kg moves according to the relation x=t2+2t3. The work done by the force in the first 2s is.
  • 7840 J
  • 1960 J
  • 3920 J
  • 4840 J
A force of 5N acts on a 15kg body initially at rest. The work done by the force during the first second of motion of the body is:
  • 5J
  • 56J
  • 6J
  • 75J
The maximum energy stored in the spring in the subsequent motion will be:
1112290_edfccfda68ab47e1858cae3f429d04e0.png
  • 15v20
  • 5v20
  • Zero
  • 10v20
A block of mass 10kg is moving in x-direction with a constant speed of 10m/sec. It is subjected to a force F=0.1x Joules/meter during its travel from x=20 meters to x=30 meters. Its final kinetic energy will be-
  • 475 joules
  • 450 joules
  • 275 joules
  • 250 joules
A chain is held on a frictionless table with L/4 hanging over. Knowing total mass of the chain is M and total length is L, the minimum work required to pull hanging part back too the table is:
  • MgL16
  • MgL8
  • MgL32
  • MgL24
The velocity of a car increase from 54km/hr to 72km/hr. How much is the work done if the mass of the car is 1500kg?
  • 231250J
  • 131250J
  • 431250J
  • 13125J
A small solid sphere of mass m is released from a point A at a height h above the bottom of a rough track as shown in the figure. If the sphere rolls down the track without slipping, its rotational kinetic energy when it comes to the bottom of track is
1110314_ea16297ee566408f878c33fb27d14c6f.PNG
  • mgh
  • 107mgh
  • 57mgh
  • 27mgh
A smooth ball A collides elastically with an another identical ball B with velocity 10m/s at an angle of 30o from the line joining their centres C1 and C2 , then mark INCORRECT statement :
1098660_fb1d401483fd4340a50d1b72884a7641.png
  • Velocity of ball A after collision is 15m/s
  • Velocity of ball B after collision is 5.4m/s
  • Both the balls move at right angles an collision
  • KE will not be conserved here, because collision is not head on
A massive disc of radius R is moving with a constant velocity u on an frictionless table. Another small disc collides with it elastically with a speed of v0=0.3 m/s, the velocities of the discs are parallel. The distance d shown in the figure is equal to R/2, friction between the discs is negligible.
For which u (in m/s) will the small disc move perpendicular to its original motion after the collision?
1346103_74b1189753bf45eca75b67e860b2c302.png
  • 1
  • 0.1
  • 2
  • 0.2
A worker lifts a 20.0kg bucket of concrete from the ground up to the top of a 20.0m tall building. What is the amount of work that the worker did in lifting the bucket?
  • 3.92kJ
  • 400J
  • 560kJ
  • 4.08J
If initial charge on all the capacitors were zero, work done by the battery in the circuit shown is 
1107793_922549ea94a743cc9e183cd3fd433c4f.jpg
  • 0.2mJ
  • 200mJ
  • 0.4mJ
  • 400mJ
A solid sphere of mass 4kg and radius 1m is rotating about the given axis xx with angular velocity 10rad/s shown in figure. The K.Erotation is given by
1123425_c8b9d82244a24874af2191bd70723295.PNG
  • 180J
  • 200J
  • 240J
  • 280J
A gun is mounted on a trolley free to move on horizontal tracks. Mass of gun and trolley 25 kg. Gun fires a two shells of mass 5 kg each other. Velocity of shells with roll to gun is 60 m/s . In above question, velocity of gun with respect to ground after firing second shell is-
  • 12 m/s
  • 18 m/s
  • 50 m/s
  • 60 m/s
Two spring of spring constant k and 3k are stretched separately by same force. The ratio of the potential energy stored in them respectively will be 
  • 3 : 1
  • 9 : 1
  • 1 : 3
  • 1 : 9
The potential energy of a particle varies with position x according to the reaction U(x)=2x427x the point x=3/2 is point of
  • Unstable equilibrium
  • Stable equilibrium
  • Neutral equilibrium
  • None of these
An object is dropped from height h=2R on the surface of earth. Find the speed with which it will collide with ground, by neglecting effect of air. [R is radius of earth. Take mass of earth as M]
  • 2GM3R
  • 2GMR
  • GMR
  • GM2
A ball of mass 10kg moving with velocity 20m/s collides elastically with wall and rebound with the same speed.Then the magnitude of change in momentum of the ball will be
  • Zero
  • 300kg m/s
  • 400kg m/s
  • 100kg m/s
In the given circuit, if point C is connected to earth and a potential of +2000V is given to a point A . Then the potential at point B is 
1117192_72a90f2333884aec8c48e628d07a6c21.PNG
  • 1500 V
  • 1000 V
  • 5000 V
  • 500 V
540 calories of heat convert 1 cubic centimeter of water at 100o C into 1671 cubic centimeter of steam at 100o C at a pressure of one atmosphere. Then the work done against the atmospheric pressure is nearly:
  • 540 cal
  • 40 cal
  • zero cal
  • 500 cal
A force F=k(xˆi+yˆj), where k is 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).
  • Work done by the force in moving particle along x-axis is 12ka2
  • Work done by the force in moving particle along x-axis is ka2
  • Work done by the force in moving particle along y-axis is 12ka2
  • Total work done by the force for overall motion is ka2
A ball moving with a velocity of 6 m/s strikes an identical stationary ball. After collision each ball moves at an angle of 30 with the original line of motion. What are the speeds of the balls after the collision?
  • 32m/sec
  • 3 m/sec
  • 23 m/sec
  • 3 m/sec
A bucket full of water weighs 5 kg, it is pulled from a well 20m deep. There is a small hole In the bucket through which water leaks at a constant rate of 0.2kgm1. The total work done in pulling the bucket up from the well is (g=10ms2)
  • 600J
  • 400J
  • 100J
  • 500J
AB is a long frictionless horizontal surface. One end of an ideal spring of spring constant K is attached to a block of mass m which is being moved left with constant velocity v1 and another end is free. Another block of mass 2m is given a velocity 3v towards the spring. The magnitude of work done by the external agent in moving m with constant velocity v in a long time is β times mv2. Find the value of β.
1171560_ebc2cffb0177469890ea81407738a004.png
  • 5 mv2
  • 8 mv2
  • 3 mv2
  • None of these
The average kinetic energy of an idea gas per molecule at 25oC, will be
  • 6.1×1020J
  • 6.1×1021J
  • 6.1×1022J
  • 6.1×1023J
The diagram shows a barrel of weight 1.0×103 N on a frictionless slope inclined at 300 to the horizontal. A force is applied to the barrel to move it up the slope at constant speed. The force is parallel to the slope. What s the work done in moving the barrel a distance of 5.0 m up the slope?
1181420_e518e92f0a9d4bb0bb848c62c5b95a7f.GIF
  • 1.0×104 J
  • 2.5×103 J
  • 4.3×103 J
  • 5.0×103 J
A smooth track in the form of a quarter circle of radius 6m lies in the vertical plane. A particle moves from P1 to P2 under the action of forces F1,F2 and F3. Force F1 is always toward P2 and is always 20N in magnitude. Force F2 always acts horizontally and is always 30N in magnitude. Force F3 always acts tangentially to the track and is of magnitude 15N. Select the correct alternative(s)  
1170161_ea1a489dfc0249d2a4da336ce2447493.png
  • work done by F1 is 120J
  • work done by F2 is 180J
  • work done by F3 is 45 π
  • F1 is conservative in nature
The collision of two balls of equal mass takes place at the origin of co-ordinates. Before collision, the components of velocities are (yx=50cm/svv=0) and (vx=40cm/s) and velocity components (vx and vy respectively) of the second ball are: 
  • 30 and 10cm/s
  • 10 and 30cm/s
  • 5 and 15cm/s
  • 15 and 5cm/s
A man raises 1 kg wt. to a height of 100 cm and holds it there for 30 minutes. How much work has he performed?
  • 1×9.8J
  • 1×9.8×30×60J
  • 1×9.8×30J
  • 1×9.8×30erg
The mass of object X is M1 and that of object Y is M2. Keeping their kinetic energy constant, if the velocity of object Y is doubled the velocity of object X, what will be the relation between their masses?
  • M1=2M2
  • 4M1=M2
  • M1=4M2
  • 2M1=M2
In a simple hydraulic press, the cross-sectional area of the two cylinders is 5×104m2 and 102m2, respectively. A force of 20N is applied at the small plunger. How much work is done by the operator, if the smaller plunger moves down 0.1m?

1157669_dabde9ab42fb43b1aa1ec11311da86ef.png
  • 40 J
  • 2 J
  • 20 J
  • 200 J
In an elastic collision which of the following is correct?
  • Linear momentum is conserved
  • Total energy is conserved
  • Kinetic energy is conserved
  • Both (1) and (2)
A practical of mass m is moving in XY plane under the action of a central force F in such a manner that at any instant t, the components of the velocity of the particle are-vx=4cost,vy=4sintThen the amount of the work done by the force in a time interval t=0 to t is-
  • zero
  • 4Ft
  • 4Ft
  • None of the above
what horizontal force f be given to the wedge of mass M so that a block of mass m placed on it remains stationary with respect to the wedge. the magnitude of the force is
  • Mg cot θ
  • (M+m)gsecθ
  • (M+m)gtanθ
  • (M+m)gcosecθ
A body of mass 5 kg falls from a height of 20 meters on the ground and it rebounds to a height of 0.2 m. If the loss in potential energy is used up by the body, then what will be the temperature rise? (specific heat of material=0.09 cal gm1 oC1)
  • 50C
  • 40C
  • 80C
  • None of these
Two identical balls A & B of mass m each are placed on a fixed wedge as shown in figure. Ball B is kept at rest and it is released just before two balls collides. Ball A rolls down without slipping on inclined plane & collide elastically with ball B. The kinetic energy of ball A just after the collision with ball B is : 
1191762_78b1742389ad486b9e1cb3547f7cd7ba.png
  • mgh7
  • mgh2
  • 2mgh5
  • 7mgh5
A uniform rod AB of length land mass m is lying on a smooth table. A small particle of mass m strike the rod with a velocity V0 at point C a distance X from the centre O. The particle comes to rest after collision. The value of x, so that point A of the rod remains stationary just after collision is:
1218859_a132437e7ac3480cb0be9225c344f366.png
  • L/3
  • L/6
  • L/4
  • L/12
A car weighing 1 ton is moving twice as fast as another car weighing 2 ton. The kinetic energy of the one-ton car is
  • less than that of the two-ton car is
  • some as that of the two-ton car is
  • more than that of the two-ton car is
  • impossible to compare with that of the two-ton car unless the height of each
A block of mass m =1 kg, moving on a horizontal surface with speed v1=2ms1 enters a rough patch ranging from x=0.10mtox=2.01m The retarding force Fr on the block in this range is 
              Fr=kx                        for 0.1 m < x < 2.01 m
                    =0                          for x<0.1 m and x > 2.01m 
where k=0.5 J
The final kinetic energy of the block is :(given ln20.13)

  • 0.5 J
  • 1 J
  • 1.5 J
  • 2 J

Two identical balls  are released from positions as shown. They collide elastically on horizontal surface. Ratio of heights attained by A & B after collision is( All surface  are smooth,neglect energy loss at M & N)


1209985_e83d8304f2d44573b6ea20a5d3daa499.PNG
  • 1:4
  • 2:1
  • 4:13
  • 2:5
A particle of mass m starts moving from origin along x-axis and its velocity varies with position (x) as v = kx. The work done by force acting on it during first 't' seconds is
  • mk4t24
  • mk2t2
  • mk4t28
  • mk2t24
Two identical balls undergo elastic collision Speed of both the balls before colision Is a, maximum possible speed of any ball after collision well be:
  • u
  • 2u
  • 3u
  • 2u
A wire suspended vertically from one of its ends is stretched by attaching a weight of 200 N to the lower end. The weight stretches the wire by 1 mm. Then the energy stored in the wire is 
  • 0.1 J
  • 0.2 J
  • 10 J
  • 20 J
A sphere of mass m moving with velocity v strikes elastically with a wall moving towards the sphere with a velocity u. If the mass of the wall is infinitely large, the work done by the wall during collision will be
  • mu(u+v)
  • 2mu(u+v)
  • 2mv(u+v)
  • 2m(u+v)
The kinetic energy of a particle moving along a circle of radius R depends on the distance covered s as T=KS2 where K is a constant. Find the force acting on the particle as a function of S -
  • 2KS1+(SR)2
  • 2KS1+(RS)2
  • 2KS1+(SR)2
  • 2SK1+(SR)2
A neutron moving with velocity u collides with a stationary αparticle The velocity of the neutron after collision is 
  • 35
  • 35
  • 25
  • 25
A body of mass 3 kg is under a constant force, Which causes a displacement s in meter in it, given by the relation s=13t2, Where t is in second. Work done by the force in 2 s is.
  • 519J
  • 38J
  • 83J
  • 195J
A tiny ball of mass 2 kg is made to move along the positive xaxis under a force described by the potential energy U shown below. It is projected towards positive xaxis from the origin with a speed v0. What is the minimum value of v0 for which the ball will escape infinity far away from the origin. 
1300390_83cf3aa624a54a889d033834fe96631a.GIF
  • 8 m/sec
  • 4 m/sec
  • 2 m/sec
  • It is not possible
A uniform rod AB of length L and mass M is lying on a smooth table. A small particle of mass m strike the rod with a velocity v0 at point C a distance x from the centre O. The particle comes to rest after collision. The value of x, so that point A of the rod remains stationary just after the collision,  is:
  • L/3
  • L/6
  • L/4
  • L/12
A uniform chain of length 2 m is kept on a table such that a length of 60 cm hangs freely from the edge of the table. The total mass of the chain is 4 kg. What is the work done in pulling the entire chain on the table? 
  • 7.2 J
  • 3.6 J
  • 120 J
  • 1200 J
A block 'A' of mass 2m placed on another block 'B' of mass 4m which in turn is placed on a fixed table. The two blocks have the same length 4d and they are placed as shown in the figure. The coefficient of friction (both static and kinetic) between block 'B' and table is μ. There is no friction between the two blocks. A small object of mass m moving horizontally along a line passing through the centre of mass (CM) of block B and perpendicular to its face with a speed v collides elastically with block B at a height d above the table. What is the minimum value of v required to make the block A topple?

1304405_f5d0de2d28504c5da848a475dee471b5.png
  • 6μgd
  • 3μgd
  • 523μgd
  • 526μgd
0:0:1


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Practice Class 11 Medical Physics Quiz Questions and Answers