Online Test

Question # 1

The peak value of an AC is 2√2 ampere.Its RMS value will be

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√2 A

2√2A

2 A

Zero

The unit of product RC is

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volt

Resistance

Second

Coulomb

The earth's potential and potential at infinity are taken:

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Equal

Zero

First is greater than the second

Second is greater than the first

Both (A) and (B)

At what point/points in its path does a projectile have its maximum speed

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At the point of projection

At the point where its strikes the ground

Both

None of these

The distance between the centres of two consecutive bright fringes (or dark fringes) is called

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wavelength

fringe width

amplitude

path difference

Radio frequency (R.F.) shielding of a coil means to protect from external circuit

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Varying magnetic field

Magnetic field

Dust and heat

Electric field

Without using a clock you want to find the time period of oscillation of a mass m attached to a spring Which of the following you will need

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Light spring

Meter scale

Known mass

All of these

A curie represents a very strong source of

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alpha particle

betta particle

gamma particle

none of them

If the mass of the uranium is much greater than the critical mass, then the chain reaction proceeds at

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Very slow speed

High speed

Rapid speed

None of these

Sound is an example of

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longitudinal waves

transverse waves

both of them

none of them

A typical rocket consumers fuel of about

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5000 Kgs^-1

10,00 Kgs^-1

10000 Kgs^-1

100000 Kgs^-1

When a gas is heated at constant pressure, its volume is increased and its density

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Increased

Increased rapidly

Decreased

None of these

A rheostat (a variable resistance) can be used as

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Variable resistor

Potential divider

Potentiometer

a and b

Computerized axial tomography (CAT-scanner) is a system in which X-rays are

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Maximum through the subject

Minimum absorptions through the subject

Depending upon the subject

None of these

Zero or low can be any voltage between:

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0 to 0.8 V

1.5 to to 2.0 V

3.5 to 5 V

2 to 5 V

What makes the hair shaving brush cling together when taken out of water

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Viscosity

Attraction between the hair

Gravity

Surface tension

In forward bias,the width of potential barrier in a p-n junction diode

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Increases

Decreases

Remains constant

First A and B

In a magnetic field the charge at rest experiences

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No Force

Maximum Force

Minimum force

None of these

Ionization of matter, when α-particle pass through it is by

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Direct elastic collision

Electrostatic attraction

Inelastic collision

a and b

Which of the following particle emit with same energy from nucleus

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α-particle

β-particle

γ-particle

None of these

The spin angular momentum is the angular momentum of a

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Rotating body

Revolving body

Spiming boy

None of these

A drop in the white blood cells followed by the radiation sickness is

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Diarrhea

Vomiting

Fever

All of these

The dielectric constant K of an insulator cannot be

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2

10

5

∞

Hook's law is defined as

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F and X are direct proportional

F and X are inverse proportional

F and X has no relation

None of these

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

In simple harmonic motion,

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The velocity and displacement of the vibrating particle are in the same phase

The velocity and acceleration of the vibrating particle are in the same phase

The velocity of the vibrating

The acceleration of the vibrating particle is ahead of displacement by a phase of π.

When a stretched string of length 'I' is plucked form one quarter of its length, the string will vibrate in

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one loop

two loops

three loops

four loops

A pendulum whose time period is 2 sec. is called

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Simple pendulum

Second's pendulum

Focault's pendulum

None of these

When T = 1.0 sec and g = 9.8 ms^-2. Find the length of the pendulum

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0.83 m

0.25 m

0.93 m

0.99 m

γ-rays of energy more than 0.5 MeV can produce

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Pair production

Compton effect

Photo electric effect

None of these

In p-type semiconductor

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Major current carrier is electrons

Major carrier is mobile negative ions

Major carrier is mobile holes

The number of mobile holes exceeds the number of acceptors

Successive dark and bright fringes are formed each time the moveable mirror in Michelsion's interferometer is moved a distance

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λ/2

λ/4

λ

3/2λ

Substances that donot flow easily are

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Honey

Thick tar

Mobile oil

All of these

A system under going forced vibrations is known as

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Driven harmonic oscillator

Vibration harmonic oscillator

Frequency harmonic oscillator

None

SI unit of potential difference is volt it can be written as

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JC^-2

JC^-1

JC

J.A

In coordinate axes, the left ward forces are taken as

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Positive

Negative

Just units only

None of these

The particles of the medium, as the wave passes through it are in phase with each other if

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they are at the same distance form equilibrium position

they are at the same distance from equilibrium position

both of them

any one of them

The relation for the diffraction pattern, when it is minimum

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d/2 sin θ = λ

sin θ = λ/2

d sin θ = λ

None of these

In diesel engine no sparking device and no need of

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Heavy current unit

Spark plug

Instant starting

None of these

Battery is charged in motor cars. Which is based.

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Chemical effect

Magnetic effect

Electric effect

None

A particle of mass 'm' at rest is acted upon by a force 'P' for a time 't' its kinetic energy after an interval 't' is

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P²t²/m

P²t²/2m

P²t²/3m

Pt/2m