Online Test

Question # 1

In which case application of angular velocity is useful?

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When a body is rotating

When velocity of body is in a straight line

When velocity is in a straight line

None of these

The gas filled in a glass tube in e/m experiment is hydrogen at

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Low pressure

Very low pressure

High pressure

None of these

Which one of the following is nearly monochromatic

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Light from candle

Light from simple lamp

Light from sodium lamp

Light from sun

The process in which energy is dissipated from the oscillating system is known as

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Resistive force

Frictional force

Damping force

None of these

The typical speed of commercial automobile (max) is

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50 ms^-1

60 ms^-1

62 ms^-1

65 ms^-1

Forα-particle and X-rays of equal absorbed dose, theα-particle are moer damaging than X-rays are

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10 times

20 times

30 times

40 times

Ideal fluid is

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Steady flow

Non-viscous

Incompressible

All of these

Which one is the example of longitudinal waves

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Sound wave

Ultrasonic

Infrasonic

All of these

The two forces of a couple do not follow the rule that

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They act on the same angle

They act in the opposite directions

They have same directions

They cancel out each other

Since there are three coils, the generator has the terminals

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Two

Four

Six

Eight

In YDS experiment, the condition for constructive interference of two coherent waves is that the path difference should be

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Integral multiple ofλ/2

Integral multiple ofλ

Even integral multiple ofλ/2

Both A and C

The magnetic field at the centre of a current carrying circular loop is B. If the radius of hte loop is doubled keeping the current the same, the magnitude filed at the centre of the loop would be

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B/4

B/2

2B

4B

When the shear stress and shear strain are involved, then their ratio is called

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Young's modulus

Bulk modulus

Shear modulus

all of them

Under a constant torque,the angular momentum of a body changes from A to 4A second find the torque.

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(3/4)A

(1/4)A

3A

(4/3)A

The modulus of rigidity of a liquid is:

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Zero

1

Infinite

None of these

Hydrogen atom does not emit characteristics X-rays because

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The electron is loosely bound

The electrons is strongly bound

Its energy levels are too close to each other

Its atomic number is low

The displacement coincides with the path of motion when a body moves along a

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Straight line

Curved path

Zig Zag path

None of these

For a body moving with constant speed in a horizontal circle,which of the following remains constant?

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Velocity

Centripetal force

Acceleration

Kinetic energy

The wave length of x-rays is of the order of

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10^-17 m

10^-4 cm

10^-9 m

10^-10 m

The application of mutual induction is a

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Television

Radio

D.C. motor

Transformer

The pressure exerted by an ideal gas can be found if the mas of a molecule, the average speed of the molecules, and the number of molecules per unit volume are known.

(Approx.) mass of one molecule

=7 x 10^-26kg

Speed = 500 m/s^-1

No. of molecules per unit volume = 5 x 10²

Find the pressure exerted

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0.0598 Pa

29.2 Pa

58.3 Pa

14.6 Pa

The two gold conducting layers enlarges the region which

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Barrier region

Deped region

Depletion region

None of these

Certain charge +q is placed at the center of a sphere. At each patch of the sphere, the directions of electric intensity and vector area are:

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Same

Different

Opposite to each other

At 60^owith each other

Both (B) and (C)

The analysis of the distribution of wavelengths of the radiation emitted from a hot body set the foundation of new mechanics,known as

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classical mechanics

Newtonian mechanics

quantum mechanics

statistical mechanics

The tracks ofγ-rays in Wilson Cloud Chamber is

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Definite and straight

No shape of track

Discontinuous tracks

None of these

Photoelectric effect means the emission of:

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Electrons from a metal at its exposure to light

protons from a metal surface

Photons from a metal surface

Photoelectrons from a metal surface

Either (A) or (D)

In a sine wave, the maximum distance at one side of its means position is

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Crest

Trough

Amplitude

All of these

Helium-Neon laser discharge tube contains neon

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82%

15%

25%

85%

An electric force which hold the charges to make atoms and molecules

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Positive charges

Negative charges

Neutral charges

a & b

Depletion region of diode is due to

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Reverse biasing

Forward biased

Absence of charge carries

None

The control rods in the atomic reactor helps to absorb the fast neutrons are

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Boron

Cadmium

Lead

All of these

The multi-mode step index optical fibre, the central core has

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high refractive index and low density

low refractive index and density

low refractive index and low density

high refractive index and high density

The SI unit of frequency is

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vibration s^-2

ms^-1

Hz

s

Isotopes have the same

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Atomic number

Mass and atomic number

Mass number

All

Aerodynamics is a branch of physics deals with the

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Thermodynamics

Hydrodynamics

Dynamics

None of these

Absolute motion cannot be detected

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in its own frame of reference

in a different frame of reference

both in its frame and different frame of reference

none of them

In insulators

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Valence band is partially filled with electrons

Conduction band is partially filled with electrons

Conduction band is empty and valence band is filled with electrons

An AC of peak value √2 A is used to heat a wire.A DC current which produced the same current of heat in the same time in the wire is

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√2 A

1A

0.707 A

√3 A

When a current-carrying conductor of length 'L' is placed in magnetic field B, this experience a force

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F = IL/B

F = ILB Sinθ

F = BI Sinθ

F = ILB Cosθ

The range of hearing of human lies between

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30 - 30,000 Hz

20 - 20,000 Hz

10 - 15,000 Hz

10 - 25,000 Hz

The mass of a proton is 1847 times that of an electron.An electron and a proton are projected into a uniform electric field in a direction at right angles to the direction of the field with the same initial kinetic energy.Then

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Both the trajectories will be equally curved

The proton trajectories will be less curved than the electron trajectory

The electron trajectory will be less curved than the proton trajectory

The relative curving of the trajectories will be dependent on the value of the initial kinetic energy.