Online Test

Question # 1

Bulk modulus for copper is

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50

75

140

147

An inductor of inductance 1.0 H in an A.C.circuit has a reactance of 500Ω The frequency of A.C will be

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100 Hz

80 Hz

50 Hz

120 Hz

An electric eye operates because of

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The Compton effect

y-radiations

Photoelectric effect

Radiations pressure

Magnetism derives its name from ______, a region in Asia Minor (Modern Turkey) where it was found in for form of certain iron core

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Magnesia

Magnesium

Electromagnetism

None of these

Due to high loop gain of the amplifier, the inverting and non-inverting inputs are

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Inverting terminal is at high potential

Non-inverting terminal is at high potential

Both are at the high potential

Both are at the same potential

Light year is measured in

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Time

Length

Speed

None of these

The work done is stretching a spring of force constant 20 Nm^-1 by an amount 30 cm is

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0.6 J

0.9 J

1.2 J

1.5 J

In which case does the potential energy decreases?

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On compressing a spring

On stretching a spring

One moving a body against gravitational force

One the rising of an air bubble in water

The horizontal component of a projectile moving with initial velocity of 500 ms^-1at an angle 60° to x-axis is

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500 ms^-1

1000 ms^-1

250 ms^-1

zero

The velocity of sound in air depends upon

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Density and elasticity of gas

Pressure

Wavelength of sound

Amplitude and frequency of sound

The component of the weight which balance the tensions

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mg sin θ

mg cos θ

mg tan θ

None of these

How many wavelengths of Kr⁸⁶ are these in one metre?

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1553164.13

1650763.73

2348123.73

652189.63

The frequency of a stretched string when it vibrates in three loops is

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equal to that of when it vibrates in one loop

double than when it vibrates in one loop

three times than when it vibrates in one loop

four times than when it vibrates in one loop

The Induced e.m.f is produced in a circuit due to:

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Initial magnetic flux through the circuit

Final management flux through the circuit

The change of magnetic flux through the circuit

None of these

When a plane polarized light is passed through certain crystals they

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Are totally absorbed

Are totally reflected

Rotate the plane of polarization

None of these

In a Millikan's oil drop experiment the charge on an oil drop is calculated to be 6.35 x 10^-19 C.The number of excess electrons on the drop is

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3.9

4

4.2

6

The application of mutual induction is a

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Television

Radio

D.C. motor

Transformer

A wave travels in all directions from its source with a velocity depending upon the properties of

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Frequency

Medium

Wave length

None of these

Bulk modulus is involved when the deformation is

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One dimensional

Two dimensional

Three dimensional

All of these

Which expression could be correct for the velocity of ocean waves in terms ofρthe density of sea water, g the acceleration due to gravity, h the depth of ocean and theλwavelength?

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For the same kinetic energy,the momentum is maximum for:

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An electron

A proton

A deuteron

An a particle

The electrostatic force of repulsion between two protons is greater than gravitational force of attraction by a factor

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10¹⁴ times

10²⁸ times

10³⁶ times

10⁴⁰ times

Fractional error in a measured quantity is determined by

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Measured value / Absolute error

Absolute error / Measured value

Measured value + Absolute error

Measured value - Absolute error

A charge of 10 C is moved along an equipotential surface having a potential of 2V. The work done is

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10 j

Zero

2 j

20 j

If two tuning forks are struck with one vibrating at 265 vib/sec and the other at 260 vib/sec, the resulting beat frequency is

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262.5 beats/sec

2.5 beats/sec

270 beats/sec

5 beats/sec

A stone is dropped from rest from the top of a tower 19.6m high.The distance traveled during the last second of its fall is (giving g = 9.8 m/s²)

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9.8 m

14.7 m

4.9 m

19.6 m

The depletion layer in the p-n junction region is caused by

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Drift of holes

Diffusion of charge carries

Migration of impurity ions

Drift of electrons

The substances in which, atom are so oriented that their field support each other and the atoms behave like tiny magnets, are called

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diamagnetic substances

ferromagnetic substances

paramagnetic substances

all of them

X-rays photons absorb in tissues and break molecular bonds and create

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Atoms

Free radicals

Highly reactive radicals

None of these

A spinning cricket ball suffers

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An extra height

An extra velocity

An extra curvature

None of these

The magnitude of torque determines its

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Linear acceleration

Angular acceleration

Moment arm

None of these

Moment of inertia does not depend upon

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Angular velocity

Mass

Position of axis of rotation

None of these

The two vectors to be combined have magnitude 60 N and 35 N. Pick the correct answer from those given below and tell why is it the only one of the three that is correct.

(i) 100 N

(ii) 70 N

(iii) 20 N

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(i) is correct

(ii) 20 N

(iii) is correct

(ii) may be correct

A body is subjected to a force such that its velocity is doubled then

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Its acceleration is also doubled

Its momentum is also doubled

Its potential energy is also doubled

Its kinetic energy is also doubled

The most abundant isotopes of neon is

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neon-20

neon-21

neon-22

neon-23

Which of the following graph represents the velocity of a spherical body falling through a viscous medium

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For small angles, the displacement of the spot of light on a scale is

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Directly proportional

Inversely proprotional

Rapidly

All of them

A rocket carries its own fuel in the form of a

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Liquid and oxygen

Solid and oxygen

Both

None of these

The current gain of transistor of collector current 100 mA and base current of 2mA will be

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200

50

10^-2

1/50

In energy conservation, when spring is stretched slowly so that acceleration is

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Maximum

Minimum

Zero

None of these

A Perpetual motion is that motion which is

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Temporary

Continuous

Forever

None of these