Question # 1

Feathers of bird give good thermal:

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Conduction

Insulation

Convection

None of these

The radius R of the earth is:

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6 x 10¹⁸m

6.4 x 10⁶m

6.4 x 10⁸m

6.4 x 10¹²m

A body has translatory motion if it moves along a.

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Straight line

Curved path

Line without rotation

Circle

In falling object potential energy is covered to:

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K.E

Force

P.E

Nil

Rate of change of momentum equals:

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Displacement

Acceleration

^Force

Velocity

Moon is nearly _________ km away from earth.

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6 x 10²⁴

380000

199.62 km

30000

The velocity of bodies falling down

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Dwscreses

Increases

Zero

Constant

Falls ceiling is done to:

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Lower the height of ceiling

Keep the roof clean

Cool the room

Insulate the ceiling

The unit of force is

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Newton

m³

ms^-2

ms^-1

If the mass of moving body in a circle is doubled then centripetal force wil be:

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Doubled

Half

4 times

Same

Brownian motion is an example of.

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Linear motion

Random motion

Circular motion

Vibratory motion

In there is no extension in the spring then this positon is called

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Equilibrium position

Unequilibrium

Nautral equilibrium

Stable equilibrium

The example of magnetic disk is:

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Compact disk

Floppy disk

Audio cassette

Video cassette

The critical angle for a beam of light passing from water into air is 48.8 degrees. This mean that all light rays with an angle of incidence greater than this angle will be:

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Absorbed

Totallly reflected

Partially reflected and partially transmitted

Totally transmitted

The digits used in electronics are:

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1

0

0 and 1

1 and 2

The process by which electrons are emitted by a hot metal surface is known as:

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Boiling

Evaporation

Conduction

Thermionic emission

Ripple tank is an instrument which is used to study the characteristics of:

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Mechanical waves

Light waves

Radio waves

Electro-magnet waves

D.C. motor converts.

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Mechanical energy into electrical energy

Mechanical energy into chemical energy

Electrical energy into mechanical energy

Electrical energy into chemical energy

The amount of current that causes the loss of muscle control is:

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0.1A

0.015A

2A

1A

According to Ohm's law V =________

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I²R

IR²

IR

I/R

The half life of Lead Pb is

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10 hour

10.10 hours

10.6 hours

1 year

Radiations present in atmosphere due to the presence of different radioactive elements are:

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Cosmic radiations

Background radiations

secondary radiations

Electromagnetic radiations

The SI unit of angular displacement is.

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Degree

Revolution

Radian

Rotation

The unit of work in base unit is

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Kg m-1 sec-2

Kgm sec-2

Kgm2 sec-1

Kgm-1 sec-1

A ray of light shows the direction of propagation of light It is line which is.

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Normal to the wave front

Parallax to the wave front

Opposite to the wave front

Equal to the wave front

A stretched string 2 m long and it has 2 hopes of stationary waves hen the wavelength is

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4 m

2 m

3 m

1 m

In rotational motion the analogous of mass is

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Angular acceleration

Torque

Moment of inertia

Angular momentum

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According to Hygen's principle, each point on a wave front acts as a source of.

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Secondary wavelet

New wave front

Sound

Primary wavelet

When the amplitude of a wave is increase to doubled is energy.

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Remain the same

Increases 4 times

Increases by two times

Decreases by half

The maximum velocity necessary to put a satellite into orbit is

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7.1 kms-1

7.3 kms-1

7.9 kms-1

8,9 kms-1

The SI unit of flow rate are

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m-sec^-2

m³-sec^-1

m³-sec^-2

m-sec^-3

SI unit of work

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Newton

Walt

Pascal

Joule

An electron in H -atom is excited from ground state n=4 , How many spectral lines are possible in this case.

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6

5

4

3

The unit of magnetic induction is:

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Tesla

Weber

Weber metre

NAm^-1

The total charge of any nucleus is:

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Ze

Z

Both a and b

None of above

Force per unit charge is called:

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Gravitational force

Electric field intensity

Coulomb's force

None of these

Maximum Compton shift is observed at.

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30^oC

90^oC

45^oC

180^oC

If the number of turns become double but length remain same, then magnetic field in the solenoid become.

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Half

Double

Remain same

Zero

Target material used in x-rays tube have following properties.

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High atomic number and high melting pouint

High atomic number and low melting pouint

Low atomic number and low melting pouint

High atomic number only

The "toner" of photocopier is given:

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Positive charge

Negative charge

Remains neutral

All of above

The negative sign with induced emf in Faraday's law is in accordance with

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Lenz's law

Amperes law

Boyle's law

Gauss law

During electrolysis process, density of CuSO₄ solution

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Remains constant

Decreased

Increased

None of these

The heat produced by passage of current.

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H=I²Rt

H=IR2T

H=I/Rt

H=I²/Rt