Question # 1

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

Two astronauts in a satellite must have

Choose an answer

Same masses

Same real weights

Same apparent weights

None of these

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?

Choose an answer

2 mgh

3 mgh

4mgh

6mgh

The equation PVr = Constant applies to:

Choose an answer

Isothermal process

Adiabatic process

Isobaric process

None of these

A diode as a rectifier converts:

Choose an answer

A)c into D)c

D)c into A)c

Varying D)c current into constant D)c current

High voltage into low voltage and vice-versa

Threshold wavelength for metal having work function 𝝋 is 𝝀. What is the threshold wavelength for metal having work function 2 𝒊𝒔:

Choose an answer

/𝟐

2

4

𝝀/𝟒

A PN junction diode cannot be use:

Choose an answer

As rectifier

For converting light energy to electrical energy

For getting light radiation

For increasing the amplitude of an ac signal

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

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

Choose an answer

1 : 2

4 : 3

2 : 3

3 : 5

When a gas is compressed:

Choose an answer

Its internal energy decreases

Its temperature decreases

Its temperature increases

None of these

While dealing with the processes i thermodynamics, the working substances is usually:

Choose an answer

Oxygen gas

Hydrogen gas

Ideal gas

None of these

If a source of emf is traversed from positive to negative the potential change will be:

Choose an answer

Positive

Negative

Zero

Constant

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

In a full wave rectifier with input frequency 50Hz. The frequency of pulsating D)C) received as an output across the load is

Choose an answer

50 Hz

100 Hz

500 Hz

zero

A body of mass m tied to a string is moved in a vertical circle of radius r. the difference in tensions at the lowest point and the highest point is.

Choose an answer

2 mg

4 mg

6 𝑚g

8 mg

The relative permittivity of air is

Choose an answer

1

3.7

7.8

1.0006

During a negative β-decayv

Choose an answer

An atomic electron is ejected

A neutron in the nucleus decays emitting an electron

An electron which already present within the nucleus is ejected

A part of binding energy of nuclei is converted into electron

A pulsating DC can be converted into constant voltage by using

Choose an answer

Filter

Full wave rectifier

Half wave rectifie

Bridge rectifier

Absolute zero is considered as that temperature at which:

Choose an answer

All liquids become gases

All gases become liquids

Water freezes

None of these

The hydrogen atoms are excited to the stationary state designated by the principal quantum number n=4, the number of maximum spectral lines are observe:

Choose an answer

2

3

4

6

The binding energy per nucleon is:

Choose an answer

Greater for heavy nuclei

Least for heavy nuclei

Greatest for light nuclei

Greatest for medium nuclei

The minimum energy required to remove an electron is called:

Choose an answer

Stopping potential

Work function

Kinetic energy

None of these

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

Choose an answer

Greater

Equal

Smaller

Undefined

The direction of angular velocity is along

Choose an answer

Tangent to the circle

Axis of rotation

Inward the radius

Out ward of the radius

Two projectiles ‘A’ and ‘B’ are thrown with same speed but at angle of 40 degree and 50 degree with the horizontal. The horizontal range of ‘A’ will be:

Choose an answer

Equal to that of ‘B’

Greater than that of ‘B’

Less than that of ‘B’

4/5times that of ‘B’

The motion of molecules in gases i:

Choose an answer

Orderly

Random

Circular

All of these

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

Capacitor stores energy in the form of :

Choose an answer

Electric field

Both of these

Magnetic field

Gravitational field

What is the resultant force in the diagram shown?

Choose an answer

Zero

6N to left

6N to right

11N to right

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

Diesel engine coverts ____________ of available heat energy into work.

Choose an answer

20% to 25%

25% to 30%

30% to 35%

35% to 40%

The nature of thermal radiation is similar to:

Choose an answer

Ultraviolet rays

Light rays

Both of them

None of them

A sonometer wire 100 cm in length has a fundamental frequency of 330 Hz. Thevelocity of propagation of waves along the wire is

Choose an answer

115m/sec

660m/sec

990m/sec

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:

Choose an answer

– 7 joules

+13 joules

+ 7 joules

+11 joules

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

A circuit that converts Pulsating DC into smooth DC contain :

Choose an answer

Filter

Capacitor

Inductor

LC circuit

Due to emission of 𝖰+ − 𝒓𝒂𝒚𝒔:

Choose an answer

Mass of the nucleus increases

Mass of the nucleus decreases

Charge on the nucleus increases

Charge number decreases

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

Choose an answer

7.5 × 1017

7.5 × 1019

5.5 × 1019

5.5 × 1017

Moving photons posses:

Choose an answer

Energy

Momentum

Wavelength

All of these

The Balmer series is found in the spectrum of:

Choose an answer

Hydrogen

Nitrogen

Oxygen

All

An electric field can deflect:

Choose an answer

X-rays

Neutrons

𝛼 −particles

𝛾 −rays