Question # 1

A particular wavelength received from a galaxy is measured on earth and isfound to be 5% more than that its wave length on earth. Hence galaxy is

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Moving towards earth

Going away from earth

Stationary with respect to earth

None

Two artificial satellites of unequal masses are revolving in a circular orbit around the earth with a constant speed. Their time periods:

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Will be different

Will depend on their masses

Will be same

Will depend upon the place of their projection

The coulomb’s law is valid for the charges which are:

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Moving and point charges

Stationary and point charges

Moving and non-point charges

Stationary and large size charges

A 50 kg man with 20 kg load on his head climbs up 20 steps of 0.25 m height each. The work done in climbing is

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5 J

350 J

100 J

3430 J

An electron is moving towards high potential. Its electrical P.E:

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Increases

Remains constant

Decrease

May increase may decrease

A magnetic field

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Always exerts a force on a charged particle

Never exerts a force on a charged particle

Exerts a force on a charged particle if it is moving across the magnetic lines of force

Exerts a force on a charged particle if it is moving along the magnetic lines of force.

Intensity of light from a point source at the edge of unit sphere will be:

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𝑃

P(4π)

4𝜋

What will be efficiency of carnot engine when it is operated between the temperatures 47^oC and 127 ^oC:

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Reversible

Irreversible

Sometimes A and B

None of these

Electromagnetic waves emitted by hot bodies are called:

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Photoelectrons

Alpha rats

Thermal radiation

None of these

While dealing with the processes i thermodynamics, the working substances is usually:

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Oxygen gas

Hydrogen gas

Ideal gas

None of these

. A force "F1" acts on a body through distance "S1" in the direction of motion and does work "W1". Similarly another force "F2" act on same body through distance "S2" but in opposite to the direction of motion and does work "W2". Now if F1 = F2 and S1 = S2 then which statement is correct.

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W1 = W2

W2< W2

W1 > W2

W1 = W2= 0

A charge is 90C passes through a wire in 1 hour and 15 minutes. Wat is the current in the wire?

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10mA

20mA

15mA

25mA

Continuous spectrum of X-rays id due to an effect known as

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Photoelectric effect

Compton effect

Heisenberg effect

Bremsstrahlung

The minimum energy required to remove an electron is called:

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Stopping potential

Work function

Kinetic energy

None of these

The body at rest may have:

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Energy

Momentum

Speed

Velocity

If the tension in a string stretched between two fixed points is made four times, the frequency of the fundamental harmonic will become:

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Two times

Three times

Four times

Six times

The maximum energy of the electrons released in a photo cell is independent of:

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Frequency of incident light

Intensity of incident light

Nature of cathode rays

None of these

The rate at which the battery is supplying the electrical energy is the:

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Power output

Electrical power

Power input

Both A and C

For a particle in circular motion the centripetal acceleration

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may be more or less than its tangential acceleration

equal to its tangential acceleration a

more than its tangential acceleration

less than its tangential acceleration

The law of thermodynamics which discusses the condition under which heat energy is converted into and equivalent amount of work is:

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1st

2nd

3rd

None of these

In electron microscope, we use high speed electrons because them

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Penetration power is higher

Wavelength is smaller

Frequency is smaller

K.E is smaller

A body revolved around the sun 27 times faster then the earth what is the ratioof their radii

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1/27

1/4

1/9

1/3

Carnot cycle is:

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Reversible

Irreversible

Sometimes A, Sometimes B

None of these

The maximum kinetic energy of emitted photoelectrons depends upon:

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The intensity of incident light

Frequency of incident light

Metal surface

Both frequency of incident light and metal surface

A 4 m long string fixed at its ends resonate in 4 segments. The wavelength of the waveis:

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4m

0.5m

2m

0.25 m

When a person lifts a body from ground work done by lifting force is?

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Positive

Negative

Zero

Half of positive maximum

A closed organ pipe and an open organ pipe have their first overtones of identicalfrequency. Their respective lengths are in the ratio:

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1 : 2

4 : 3

2 : 3

3 : 5

It is a common characteristic of all types of wave motion that

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Particles move up and down

Particles move back and forth

Energy is transferred without the transport of particles

A material medium transmits the disturbance

The spectrum of a star’s light is measured and the wavelength of one of the lines as thesodium’s line is found to be 589 nm. The same line has the wavelength of 497 nm whenobserved in the laboratory. This means the star is

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Moving away from the earth

Moving towards the earth

Stationary

Revolving around the planet

Avogadro number is known as number of molecules in:

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One kg of a substance

Unit volume of a substance

One mole of a substance

None of these

What is the resultant force in the diagram shown?

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Zero

6N to left

6N to right

11N to right

A ball takes ‘t’ second to fall from a height 𝒉𝟏 and ‘2t’ second to fall from a height 𝒉𝟐 then h1/h2 is:

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2

4

0.5

0.25

If the radius of the circular path of particle going around the circle is doubled without changing its frequency of rotation, then centripetal force on it is.

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doubled

halved

unchanged

quadrupled

In a gravitational field when work done by gravity is negative then

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P.E increases

P.E decrease

None

P.E remains same

A stone attached to one end of a string is revolved around a stick so that the string winds on the stick and gets shortened) What is conserved)

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angular momentum

kinetic energy

linear momentum

none of the above

The ratio of the longest and shortest wavelength of the Lyman series is approximately:

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4/3

9/4

9/5

16/7

Interference and diffraction of light confirms its:

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Particle nature

Dual nature

Wave nature

Electromagnetic nature

Half-life of radon gas is:

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1620 years

3.8 days

7 days

11 days

The energy stored in wound watch spring is

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K.E.

P.E.

heat energy

chemical energy

An engine pumps up 100 kg of water through a height of 10m in 5s. Given that the efficiency of the engine is 60%, what is the power of the engine? (Take g = 10ms^-2)

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33 kW

3.3kW

0.33kW

0.033kW

If temperature of the sink is decreased, efficiency of a carnot engine.

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Remains constant

Decreases

Increases

None of these