MCQS | The dot product of force and velocity is

Question :- ________________ cells converts solar energy into electrical energy

1.rotory

2.photovoltaic

3.galvanic

4.non of these

Question :- A man lifts vertically a weight of 40kg through 1m in 10s; while a chile lifts vertically a weight of 10kg through a distance of 1m in 1s. What will be correct inference?

1.man does more work than child

2.child does more work than man

3.both do the same amount of work

4.it is a foolish question

Question :- A simple pendulum suspended form the ceiling of a lift has time period T when the lift is at rest. When the lift falls freely, the time period is

1.infinite

2.T/g

3.zero

4.g/T

Question :- Biomass can be converted into fuels by

1.direct combustion

2.fermentation

3.both (a) and (b)

4.none of these

Question :- For what displacement the P.E becomes 1/4 of its maximum value?

1.x = x?

2.x = x?/2

3.x = x?/4

4.x = x?2/2

Question :- Geothermal energy is a ____________________ source of energy.

1.non-renewable

2.stable

3.renewable

4.none of the above

Question :- Gravitational P.E of a body has

1.no formula

2.a formula mgh only

3.a formula

4.no general formula

Question :- If length of second pendulum becomes four times, then its time period will become

1.four times

2.six times

3.eight times

4.two times

Question :- If moon radius is 1600 km and g on its surface is 1.6 ms-2 then the escape velocity on the moon is

1.1600 ms-1

2.50.6 ms-1

3.71.6 ms-1

4.2263ms-1

Question :- If velocity is doubled then

1.momentum increases 4 times and K.E increases 2 times

2.momentum and K.E. remain same

3.momentum increases 2 times and K.E increases constant

4.momentum increases 2 times and K.E increases 4 time

Question :- In S.H.M. the velocity of a particle is maximum at

1.mean position

2.extreme position

3.middle between mean and extreme position on the right side

4.middle between mean and extreme position on the left side

Question :- In vibratory motion

1.P.E. remains constant

2.K.E. remain constant

3.total energy remain constant

4.total momentum remain constan

Question :- On a clear day at noon the solar energy reaching the earth is

1.1.44kw/m2

2.1.4kw/m2

3.1 kw/m2

4.none

Question :- One mega watt hour is equal to

1.36 x 106 J

2.36 x 1012 J

3.36 x 109 J

4.36 x 108 J

Question :- Propulsion force of a rocket is

1.non-conservative force

2.conservative force

3.both (a) and (b)

4.non of these

Question :- S.I unit of frequency is

1.vibration S-2

2.radian

3.hertz

4.ms-1

Question :- Simple harmonic motion is a type of

1.rotational motion

2.circular motion

3.musical arrangement

4.vibratory motion

Question :- The acceleration of a projection on the diameter for a particle moving along a circle is

1.w2x

2.wx2

3.w2x

4.wx2

Question :- The area under the force displacement graph represents

1.area

2.work done

3.power

4.none of these

Question :- The consumption of energy by a 60 watt bulb in 2 sec is

1.120 J

2.60 J

3.30 J

4.0.02 J

Question :- The dimension of power is

1.[ML2T-3]

2.[ML2T-2]

3.[ML2T3]

4.none of these

Question :- The displacement of SHM is written as X = X? sin?t if displacement is written by X = X? son ?t then phase constant will be equal to

1.0?

2.45?

3.90?

4.180?

Question :- The dot product of force and velocity is

1.power

2.work

3.impulse

4.torque

Question :- The energy of SHM is maximum at

1.mean position

2.extreme position

3.in between mean and extreme

4.all positions during SHM

Question :- The escape velocity form the earth surface in km S-1 is

1.4.2 km S-1

2.7.5 km S-1

3.9.5 km S-1

4.1.1 km S-1

Question :- The escape velocity of a body in gravitational field of earth is independent of

1.its mass

2.the angle at which it is thrown

3.both its mass and the angle at which it is thrown

4.gravitational field of earth

Question :- The force responsible for the vibratory motion of the simple pendulum is

1.mg cos?

2.mg sin?

3.mg ton?

4.mg

Question :- The frequency of the second pendulum is

1.1 hertz

2.0.5 hertz

3.1.5 hertz

4.2.5 hertz

Question :- The highest value of escape velocity in solar system is planet

1.Earth

2.Neptune

3.Jupiter

4.Moon

Question :- The length of second pendulum is

1.100 cm

2.99 cm

3.99.2 cm

4.98 cm

Question :- The product of frequency and time period is equal to

1.1

2.2

3.3

4.4

Question :- The relation between the escape velocity V esc and orbital speed Vo is given by

1.V esc = 1/2Vo

2.V esc = ?2 Vo

3.V esc = Vo

4.V esc = 2Vo

Question :- The SI unit of force constant is identical with that of

1.force

2.pressure

3.surface tension

4.loudness

Question :- The source of geothermal energy is

1.decay of radioactive element in the earth

2.compression of material in the earth

3.residual lost of the earth

4.all as said in a - b and c

Question :- The source of tidal energy is

1.sun

2.earth

3.both (a) and (b)

4.moon

Question :- The tides raise the mater in the see roughly in a day

1.once

2.twice

3.four time

4.eight time

Question :- The time period of a second pendulum is

1.4 seconds

2.3 seconds

3.2 seconds

4.6 seconds

Question :- The waveform of S.H.M. is

1.standing wave

2.sine wave

3.square wave

4.none

Question :- The work done by friction is

1.positive

2.negative

3.zero

4.none of these

Question :- Total energy of a body executing S.H.M is directly proportional to

1.square root of amplitude

2.the amplitude

3.reciprocal of amplitude

4.square of amplitude

Question :- When arrow is released form its bow, its energy is transformed from

1.heat energy to K.E

2.elastic P.E to K.E

3.elemical energy to elastic P.E

4.K.E to elastic P.E.

Question :- When the amplitude of a wave become double its energy become

1.double

2.four times

3.one half

4.none time

Question :- When the speed of a moving body is doubled then

1.its K.E is doubled

2.its acceleration is doubled

3.ts P.E is doubled

4.its momentum is doubled

Question :- When two protons are brought together

1.Kinetic energy increases

2.P.E. between them increases

3.P.E. between them decreases

4.P.E. between tem does not change

Question :- Which of the following is not conservative force

1.friction

2.electric

3.gravitational

4.magnetic

Question :- Work done by the force of friction is

1.always positive

2.always negative

3.positive only for small frictional force

4.positive only for large frictional force

Question :- Work done by variable force is determine by dividing

1.force into small interval

2.displacement into small interval

3.both force and displacement into small intervals

4.force into small and displacement into large intervals

Question :- Work done on the body equals to the

1.change in its K.E always

2.change in its P.E always

3.change in its K.E and change in its P.E

4.neither change in K.E and nor change in its P.E

Question :- Work has the dimension as that of same as that of

1.torque

2.angular momentum

3.linear momentum

4.power