Question # 1

In photoelectric effect experiment, stopping potential depend upon

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Intensity of light

Frequency of light

Photoelectric current

Both A and B

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

Ten second after an electric fan is turned on, the fan rotates at 300rev/min. its average angular acceleration is

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30 rad/s²

3.14 rad/s²

30 rev/s²

500 rev/s²

The relative permittivity of air is

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1

3.7

7.8

1.0006

Two wires of same material have lengths L and 2L and cross-sectional area 4A and A respectively. the ratio of their specific resistance would be:

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1: 1

1: 8

8: 1

1: 2

The force which provides the necessary centripetal force to keep the mud in circular path is called

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cohesive force

adhesive force

frictional force

gravitational force

The rate of change of momentum of a molecule is equal to:

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Pressure

Work

Density

Force

Which of the following work is greater?

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+ 100J

0 J

- 100J

Both A and B are equal

In which process the change in internal energy of the system is zero:

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Isochoric process

Isobaric process

Adiabatic process

Isothermal process

The mud flies off the tyre of a fast moving car in the direction

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parallel to the moving tyre

anti parallel to the moving tyre

tangent to the moving tyre

none of these

Wavelength of the wave is the distance between the particles of the medium having adifference of:

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Zero

n

2n

𝜋2

A circuit that converts Pulsating DC into smooth DC contain :

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Filter

Capacitor

Inductor

LC circuit

A rigid uniform bar of length 2.4 m is pivoted horizontally at its mid-point, weights are hung from two points of the bar as shown in diagram. To maintain horizontal equilibrium, a couple is applied to the bar: What is the torque and the direction of couple?

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40 N m clockwise

40 N m anti-clockwise

80 N m clockwise

80 N m anti-clockwise

An electron and a proton are projected at right angles to a uniform magnetic field with

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the electron trajectory will be less curved than proton’s trajectory

the electron trajectory will be more curved than proton’s trajectory

) both trajectories will be equally curved

) both particles continue to move along a straight lins

A photo cell is based on:

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Compton effect

Pair production

Photo cell

All of these

For atomic nucleus, the binding energy per nucleon with increase in mass number:

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Increases continuously

Remains same

Decrease continuously

First increases and then decreases with increase in mass number

If a molecule with momentum mv strikes a wall and rebound then the change in momentum will be:

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-2 mv

Zero

2 mv

mv

The Balmer series is found in the spectrum of:

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Hydrogen

Nitrogen

Oxygen

All

The energy of photon of wavelength 620 nm is:

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0.5 eV

1.0 eV

1.5 eV

2.0 eV

For X-rays which of the following is not correct:

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Cause of ionization in air when they pass through it

Can be deflected by electric and magnetic fields

Can be used to detect flaws in metal casting

Travel with the speed of light

An electric field can deflect:

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X-rays

Neutrons

𝛼 −particles

𝛾 −rays

The binding energy per nucleon is:

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Greater for heavy nuclei

Least for heavy nuclei

Greatest for light nuclei

Greatest for medium nuclei

The frequency and work function of an incident photon are n and𝝋𝟎. If f0 is the threshold frequency, then necessary condition for the emission of photo electron is:

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< 𝑓0

𝑓 ≥ 𝑓0

f = 𝑓0/2

None of these

The energy of photon of wavelength 1240 nm is:

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0.5 eV

1.0 eV

1.5 eV

2.0 eV

The maximum energy of the photoelectrons depends upon:

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Frequency of incident light

Intensity of incident light

Nature of metal

Both (a) & (c)

When resistances are connected in Parallel, the effective resistance will be

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Product of the reciprocals of the individual resistances

Product of the individual resistances

Sum of the reciprocals of the individual resistances

Sum of the individual resistances

When a particle moves in a circle the angle between it linear velocity and the angular velocity is always

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0°

180°

90°

none of them

The unit of gain (G) for non-inverting amplifier is

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Ampere

ohm

Volt

None of these

In Compton effect, it was considered that X-rays consist of:

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Electrons

Positrons

Photons

All of these

Diesel engine coverts ____________ of available heat energy into work.

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20% to 25%

25% to 30%

30% to 35%

35% to 40%

When heat is added to the system, the entropy change is:

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Positive

Negative

Zero

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 particle executing one dimensional motion, finally comes to rest, what will be the angle between

acceleration and displacement during motion:

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0

π

𝜋/2

𝜋/4

The radius of orbit of a geostationary satellite depends upon:

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Mass of satellite and its time period

Mass of satellite and mass of earth

Mass of earth, mass of satellite and time period of satellite

Mass of earth and time period of earth

A source of a magnetic field is:

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An isolated magnetic

A static electric charge

A moving electric charge

None of these

Which of the particles, electron, proton and neutron moving with same speed has longest wave length?

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Electron

Proton

Neutron

All have same

The gravity does no work, when the body moves:

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Horizontally

Vertically upwards

Vertically downward

At an angle of 45o with horizontal

To find longest wavelength radiation in Ballmer series, the value of n used is:

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2

3

4

∞

A particle executing one dimensional motion, finally comes to rest, what will be the angle between acceleration and displacement during motion:

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0

π

𝜋/2

𝜋/4

The magnetic field of a solenoid is quite similar to that of a:

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Straight conductor

A horse shoe magne

Any magnet

A bar magnet

When a dielectric is inserted between the plates of a capacitor, Which one is true

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Energy stored increase

Energy stored decrease

Capacitance decrease

All