Question # 1

In thermodynamics, the change in internal energy depends upon:

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The path taken between initial and final states

The initial state only

The final state only

Initial and final states

In the theory of dimensional analysis, heat may be properly represented by:

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ML²T^-2

MT^-2

ML^-1T^-1

None of these

The maximum energy of the electrons released in a photo cell is independent of:

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Frequency of incident light

Intensity of incident light

Nature of cathode rays

None of these

A photo cell is based on:

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Compton effect

Pair production

Photo cell

All of these

A body moves a distance of 10 m along a straight line under the action of a force of 5 N. If the work done is 25 joules, the angle which the force makes with the direction of motion of the body is?

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0 Degree

30 Degree

60 Degree

90 Degree

When ultraviolet rays are incident in metal plate, then photoelectric effect does not occur. It occurs by the incidence of:

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x-rays

Infrared rays

Radio wave

Greenhouse effect

With the propagation of longitudinal waves through a material medium, the quantitiestransferred in the direction of propagation are:

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Energy, momentum and mass

Energy and momentum

Energy and mass

Energy

On slightly disturbing a body which is an unstable equilibrium, its center of gravity

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rises

falls

remains constant

first rises then falls

Angular displacement in rotational motion is expressed in

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m

m²

Nms-1

Nm s

It is a common characteristic of all types of wave motion that

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Particles move up and down

Particles move back and forth

Energy is transferred without the transport of particles

A material medium transmits the disturbance

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

If the radioactive substance reduces to 𝟏 𝟏𝟔 PHYSICS of its original mass in 40 days then its half-life is:

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10days

20days

40days

4days

Inverting amplifier circuits have

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A very high input impendance

A very low input impendance

A low output impendance

Both A and C

When the radioactive nucleus emits a beta particle, the proton neutron ration:

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increases by one

Remains same

Decreases by one

Decreases by four

A man weighing 500 N carries a load of 10 kg to the top of a building in 4 minutes. The work done by the man is 6 × 𝟏𝟎⁴ J. If he carries the same load in 8 minutes, the work done by the man will be:

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3 × 10⁴ J

6 × 10⁴J

9 × 10⁴J

12× 10⁴ J

G.P Thomson revealed:

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Particle nature of electron

Dual nature of electron

Wave nature of electron

Electromagnetic nature of electron

The energy of photon of wavelength 1240 nm is:

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0.5 eV

1.0 eV

1.5 eV

2.0 eV

Wavelength of the wave is the distance between the particles of the medium having adifference of:

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Zero

n

2n

𝜋2

A stationary wave is established in a string which vibrates in four segments at afrequency of 120 Hz. Its fundamental frequency is:

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15Hz

60Hz

30Hz

430Hz

For a normal AC cycle, during T/2 to T the diode act as:

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Open switch

full wave rectifier

Close switch

All are correct

What will be the number of photons emitted per second by 25 W source of monochromatic light of wavelength 600 nm:

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7.5 × 1017

7.5 × 1019

5.5 × 1019

5.5 × 1017

A force 𝑭 = (𝟓𝒊̂+ 𝟑𝖩̂) newton is applied over a particle which displaces it from its origin to the point 𝒓 = (𝟐𝒊̂− 𝟏𝖩̂) meters. The work done on the particle is:

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– 7 joules

+13 joules

+ 7 joules

+11 joules

First law of thermodynamics is merely a statement of law of conversation of:

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Energy

Angular momentum

Change

Linear momentum

The more readily fissionable isotope of uranium has an atomic mass of:

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220

230

235

240

If the K.E. of a body is increased by 300%, its momentum will increase by:

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100 %

150 %

√300%

175 %

In full wave rectification by bridge the number of diodes required are

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3

4

2

5

Two railway trucks of masses m and 3m move towards each other in opposite directions with speeds 2v and v respectively. These trucks collide and stick together. What is the speed of the trucks after the collision?

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v/4

v/2

v

5v/4

If a transverse wave has a speed of 10 m/ sec and frequency of 10 cycle/ sec itswavelength is:

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1 m

10^-2 cm

10 m

10 cm

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

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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

For the same value of resistors the output of non-inverting amplifier compared to the output of inverting amplifier is, (ignoring phase difference)

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Greater

Equal

Smaller

Undefined

If P is the pressure and V is the volume, Then PV will represent:

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Power

Work

Force

None of these

Intensity of light from a point source at the edge of unit sphere will be:

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𝑃

P(4π)

4𝜋

Photoelectric effect and Compton effect prove the:

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Wave nature of light

Particle nature of light

Dual nature of light

A rider uses Motorcycle safety helmet that extends the time of collision during accident hence decreasing the

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Change of collisio

Force acting

Velocity

Impulse

The mother and daughter elements with the emission of 𝖰 − 𝒓𝒂𝒚𝒔, are called:

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Isotopes

Isobars

Isomers

Isodiapheres

Choose incorrect about properties of photon

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Rest mass of photon is zero

A photon is never at rest

Photon is not deflected by electric field not by magnetic field

The velocity of photon is different in different media

The magnitude of potential barrier for Ge is

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0.7 v

0.3 V

7v

3 v

Most motorbikes have ____________ cylinder/s engine but cars usually have _________ cylinders on the same crankshaft.

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Four , Six

One , four

two , five

None of these

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

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A. A long the circumference of the circle

Along the tangent

Along the radius

Zero

A closed organ pipe and an open organ pipe have their first overtones of identicalfrequency. Their respective lengths are in the ratio:

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1 : 2

4 : 3

2 : 3

3 : 5

Car X is traveling at half the speed of car Y. Car X has twice mass of car Y.

Which statement is correct?

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Car X has half the kinetic energy of car Y

Car X has one quarter of the kinetic energy of car Y

Car X has twice the kinetic energy of car Y

The tow cars have the same kinetic energy