Question # 1

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

Choose an answer

Moving away from the earth

Moving towards the earth

Stationary

Revolving around the planet

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

Choose an answer

4g

3g

g

6g

Photo cells is a device which convert light into:

Choose an answer

Wave nature

Particle nature

Particle wave nature

Dual nature

A body is dropped from a height of 20 m and rebounds to a height of 10 m. the loss of energy is:

Choose an answer

10%

45%

50%

75%

Speedometer of an automobile measures

Choose an answer

Average velocity

Instantaneous velocity

Acceleration

Instantaneous speed

In closed end organ pipe, the frequency of first harmonic is 300 Hz. The frequency ofthird overtone is :

Choose an answer

900 Hz

1500 Hz

2100 Hz

600 Hz

Two bodies are projected at angle 𝜽 𝒂𝒏𝒅 (𝟗𝟎 − 𝜽) to the horizontal with the same speed. The ratio of their times of flight is:

Choose an answer

sin 𝜃 : 1

cos 𝜃 : 1

sin 𝜃 : cos𝜃

cos 𝜃 : sin𝜃

The fundamental frequency of a closed organ pope is 50 Hz. The frequency ofsecond over tone is

Choose an answer

100hz

150hz

60hz

250hz

Which of the following does not have the same units:

Choose an answer

Work

Heat

Kinetic energy

Power

If the momentum of a body is increased n times, its kinetic energy increases:

Choose an answer

n times

2 n times

√𝑛 times

n 2 time

You lift a suit case from the floor and keep it on a table. The work done by you on the suitcase does not depend on

Choose an answer

the path taken by the suitcase

weight of the suitcase

initial and final position

None

When a gas is compressed:

Choose an answer

Its internal energy decreases

Its temperature decreases

Its temperature increases

None of these

The force which can do no work on the body on which it acts:

Choose an answer

Frictional force

Elastic force

Gravitational force

Centripetal force

The geostationary satellite is:

Choose an answer

Stationary

Rotating very fastly

Rotating with the period of earth

Rotating very slowly

𝑎, 𝖰 𝒂𝒏𝒅 radiations come out of radioactive substance:

Choose an answer

Spontaneously

When it is put in a reactor

When it is heated

Under pressure

A machine gun fires ‘n’ bullets per second and the mass of each bullet is m. If v is the speed of each bullet then the force exerted on the machine gun is:

Choose an answer

mng

mnv

mnvg

mnv/g

De-Broglie received the Nobel prize on his work on:

Choose an answer

Wave nature of particle

Corpuscular nature of wave

Dual nature of particle

All of them

If the distance between the plates of a parallel plates capacitor is increased, its potential will:

Choose an answer

Remain the same

Increase

Decrease

Decrease exponentially

Real gases strictly obey gas laws at:

Choose an answer

High pressures and low temperatures

Low pressures and high temperatures

High pressures and & temperatures

None of these

select Which one of the following is not performing projectile motion

Choose an answer

A gas filled balloon

) Bullet fired from gun

A football kicked

A baseball shot

The distance covered by a body in time ‘t’ starting from rest is:

Choose an answer

1/2 𝑡²

vt

𝑎𝑡²

𝑎𝑡₂

As the working substance of a heat engine completes a cycle, there is no change in:

Choose an answer

Internal energy

Pressure

Volume

All of these

The ratio of the SI unit to the C)G.S unit of torque is.

Choose an answer

10⁷

10⁹

10⁰

10³

Moving photons posses:

Choose an answer

Energy

Momentum

Wavelength

All of these

The body at rest may have:

Choose an answer

Energy

Momentum

Speed

Velocity

A ball is thrown vertically upwards. Neglecting air resistance, which statement is correct?

Choose an answer

The kinetic energy of the ball is greatest at the greatest height attained

The potential energy of the ball increase uniformly with time during the ascent

By the principle of conservation of momentum. The momentum of the ball is constant throughout its motion

By the principle of conservation of energy, the total energy of the ball is constant throughout its motion

Charge on a capacitor is 50C. if voltage applied across its plates is 10V then its capacitance:

Choose an answer

5F

0.02F

500F

0.2F

A particle revolves round a circular path with a constant speed. The accelerationof the particle is

Choose an answer

A. A long the circumference of the circle

Along the tangent

Along the radius

Zero

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

Choose an answer

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

For X-rays which of the following is not correct:

Choose an answer

Cause of ionization in air when they pass through it

Can be deflected by electric and magnetic fields

Can be used to detect flaws in metal casting

Travel with the speed of light

A man pushes a wall and fails to displace it. He does:

Choose an answer

Negative work

Positive but not maximum work

No work at all

Maximum work

Two artificial satellites of unequal masses are revolving in a circular orbit around the earth with a constant speed. Their time periods:

Choose an answer

Will be different

Will depend on their masses

Will be same

Will depend upon the place of their projection

A monkey is accelerating down a string whose breaking strength is two third of his weight. The minimumacceleration of the monkey should be

Choose an answer

1/3g

g

2/3 g

0 m/s2

As the intensity of incident light increases:

Choose an answer

Photoelectric current increases

Photoelectric current decreases

Kinetic energy of emitted photoelectrons increases

Kinetic energy of emitted photoelectrons decreases

The temperature at which all the gases become liquid is called:

Choose an answer

273 K

-273 K

Absolute Zero

Both (B) and (C)

The law, governing the force between electric charges is known as:

Choose an answer

Ampere’s law

Ohm’s law

Coulomb’s law

Faraday’s law65y7uhnb

Area under Q-V graph for a capacitor represents

Choose an answer

Charged stored

Energy stored

Electric field strength

Potential difference

The simplest type of rectification known as half wave rectification is obtained by

Choose an answer

Using a transistor

Suppressing the harmonics in A.C. voltage

Suppressing half wave of A.C. supply by using diode

Using a Coolidge

The energy of photon of wavelength 620 nm is:

Choose an answer

0.5 eV

1.0 eV

1.5 eV

2.0 eV

The rate at which the battery is supplying the electrical energy is the:

Choose an answer

Power output

Electrical power

Power input

Both A and C

Number of spark plugs needed in diesel engine is:

Choose an answer

Four

Five

Six

None of these