Question # 1

The geostationary satellite is:

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Stationary

Rotating very fastly

Rotating with the period of earth

Rotating very slowly

The ‘emf ’ is always even when no current is drawn through the battery of the cell:

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Zero

Present

Absent

Maximum

A PN junction diode cannot be use:

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As rectifier

For converting light energy to electrical energy

For getting light radiation

For increasing the amplitude of an ac signal

Charge to mass ratio (e/m) of a charge particle is also called its:

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Specific charge

Specific Force

Gyro-magnetic ratio

Magneto-mechanical ratio

In a photocell, sodium and potassium emit electrons for:

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Visible light

Infrared light

Ultraviolet light

All of these

A human eye can detect the electromagnetic radiations of the type:

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Infrared radiations

For- infrared radiations

X-rays radiations

Red radiations

For a particle moving in uniform circular motion

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Velocity is transverse and acceleration is radical

Velocity is radial and acceleration is transverse

Both velocity and acceleration are radial

Both velocity and acceleration are transverse

The frequency of an open pipe is f. if one end is closed then its fundamental frequencywill be:

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f/2

3f/4

f

2f

Carnot cycle is:

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Reversible

Irreversible

Sometimes A, Sometimes B

None of these

A body crosses the topmost point of a vertical circle with critical speed. Itscentripetal acceleration, when the string is horizontal will be

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4g

3g

g

6g

The number of electrons in a nucleus X of atomic number Z and mass number A is:

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A

W

Z

Y

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

A.H Compton studied the scattering of X-rays by loosely bound electrons from a graph target in:

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1905

1911

19251

1923

The wavelength of light observed on the earth, form a moving star is found todecrease by 0.05%. Relative to the earth the star is

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moving away with a velocity of 1.5 x 10⁵m/s

moving away with a velocity of 1.5 x 10⁴m/s

coming closer with a velocity of 1.5 x 10⁵m/s

coming closer with a velocity of 1.5 x 10⁴m/s

Initially, four identical uniform blocks, each of mass m and thickness h, are spread on a table How much work is done on the blocks in stacking them on top of one another?

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2 mgh

3 mgh

4mgh

6mgh

For a particle in circular motion the centripetal acceleration

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may be more or less than its tangential acceleration

equal to its tangential acceleration a

more than its tangential acceleration

less than its tangential acceleration

A human eye can detect the electromagnetic radiations of the type:

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Infrared radiations

For- infrared radiations

X-rays radiations

Red radiations

When passes from medium to another, deviate from its path is called

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reflection

refraction

diffraction

transmission

If the velocity of a body becomes half, the kinetic energy of body will become

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One fourth

Double

Four times

Half

The nature of thermal radiation is smaller to:

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Ultraviolet rays

Light rays

Both of them

None of these

A body is moving in a circle with a constant speed. it has

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a constant velocity

a constant acceleration

a velocity of constant magnitude

an acceleration of constant magnitude

The body at rest may have:

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Energy

Momentum

Speed

Velocity

The spectrum of a star’s light is measured and the wavelength of one of the lines as thesodium’s line is found to be 589 nm. The same line has the wavelength of 497 nm whenobserved in the laboratory. This means the star is

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Moving away from the earth

Moving towards the earth

Stationary

Revolving around the planet

What is the resultant force in the diagram shown?

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Zero

6N to left

6N to right

11N to right

Petrol engine coverts ____________ of available heat energy into work.

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20% to 25%

25% to 30%

30% to 35%

35% to 40%

The angular momentum changes form 2 units to 6 units in 4s. the torque is

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1 unit

3/2unit

1/2unit

4unit

A process in which no heat enters or leaves the system is called.

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Adiabatic process

Isothermal process

Isochoric process

None of these

An elevator's motor produces 3000 W power. The speed With Which it can lift a 1000 kg load is:

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30.6ms^-1

0.306ms^-1

3.06ms^-1

300.3ms^-1

The most penetrating radiations out of the following is that of

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𝛾-rays

β-rays

α-particles

X-rays

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

As in linear motion force determines linear acceleration where as in circular motion torque determines its

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Angular acceleration

Linear acceleration

Vibratory acceleration

Tangential acceleration

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

A motor boat is travelling with a speed of 3.0 m/sec. If the force on it due to water flow is 500 N, the power of the boat is

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150 KW

1.5 KW

heat energy

chemical energy

A body moving in a circular path with a constant speed has a

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Constant velocity

Constant kinetic energy

Constant acceleration

Constant displacement

Newton’s third law concerns the forces of interaction between two bodies. Which of the following statement relating to the third law is not correct:

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The two forces must be the same type

The two forces must act on different bodies

The two forces are always opposite in direction

The two forces are equal and opposite so the bodies are in equilibrium

Work done in raising a box depends on:

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How fast it is raised

The strength of the man

The height by which it is raised

None of the above

Two bodies are projected at angles  and (90°–) with the horizontal at the same speed.The ratio of their maximum heights is

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1 : 1

1 : tan 

tan² : 1

The rate of change of momentum of a body falling freely under gravity is equal to its

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Impulse

Kinetic energy

Pover

Weight

Tick which of the following is not state variable:

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Heat energy

Pressure

Entropy

Volume

The same retarding force is applied to stop a train. The train stops after 80 m. If the speed is doubled, then the Stopping distance will be:

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The same

Doubled

Halved

Four times

A radioactive isotope 𝟐𝟑𝟖 𝑼 decays consecutively to 𝟐𝟑𝟒 𝑼 the particles emitted are:

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One 𝛼 and one 𝛽

Two 𝛼 and one 𝛽

e 𝛼 and two 𝛽

Two 𝛼 and two 𝛽