Question # 1

A church organ consist of open ended pipes ranging from 4m to 4 mm, if the speed ofsound is considered as 400 m/s then the min and max frequency is:

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400 Hz and 4 kHz

100 Hz and 100 kHz

50 Hz and 50kHz

400 Hz and 400 kHz

The gravity does no work, when the body moves:

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Horizontally

Vertically upwards

Vertically downward

At an angle of 45o with horizontal

Change in momentum per second is:

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Product force and time

Product of pressure and area

Ratio of pressure and area

None of these

The efficiency of full wave rectifier is:

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25.6%

81.2%

81.6%

71.2%

The radius of orbit of a geostationary satellite depends upon:

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Mass of satellite and its time period

Mass of satellite and mass of earth

Mass of earth, mass of satellite and time period of satellite

Mass of earth and time period of earth

In case of planets the necessary acceleration is provided by

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Gravitational force

coulomb force

frictional force

centripetal force

A photo cell is based on:

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Compton effect

Pair production

Photo cell

All of these

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:

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sin 𝜃 : 1

cos 𝜃 : 1

sin 𝜃 : cos𝜃

cos 𝜃 : sin𝜃

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

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n times

2 n times

√𝑛 times

n 2 time

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

Which of the following have maximum ionization power?

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𝛼 −rays

𝛽 −rays

𝛾 −rays

Same for all

A string vibrates in 1 loop has frequency 25 Hz if it moves in 2 loops its frequencywould be:

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25 Hz

50 Hz

12.5 Hz

5Hz

A tritium and alpha particle enter the magnetic field with same kinetic energy, what will be the ratio of their radii?

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3:4

√3: 1

√3: 4

√3:√2

electrons from the surface of a metal when:

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It is heated to a high temperature

Radiation of suitable wavelength falls on it

Electrons of suitable velocity strike it

It is placed in a strong electric field

A couple produces

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linear motion

rotational motion

both (A) and (B)

None

A stone of mass 0.5kg tied with a string of length 1m is moving in a horizontal circle with a speed of 4ms-1 . The tension acting on the string in newton is:

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2

0.2

8

0.8

Photo cells is a device which convert light into:

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Wave nature

Particle nature

Particle wave nature

Dual nature

An electric field can deflect:

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X-rays

Neutrons

𝛼 −particles

𝛾 −rays

In the absence of air resistance, a stone is thrown from P and follows a parabolic path in which the highest point reached is T. The vertical component of acceleration of stone is:

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Zero at T

Greatest at T

) Greatest at P

the same at P as at T

The diode charactristics curve is plot between

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I & t

V& t

V& I

None

If a rotating body is moving counter clockwise, direction of angular velocity will be

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along linear velocity

towards the center

along the axis of rotation

away from center

Capacitor stores energy in the form of :

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Electric field

Both of these

Magnetic field

Gravitational field

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

The pressure exerted on the walls on the vessel by gas molecules is defined as:

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Force per unit volume

Energy per unit area

mass per unit volume

None of these

A thorium nucleus is formed when a uranium nucleus emits an 𝑎 −particles. Atomic number of thorium is :

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23

60

90

70

Brownian motion confirms the truth of :

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Wave theory of light

Boyle's law

Kinetic theory of gases

Adiabatic process

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

The ideal gas obey gas law at:

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Low tempratures and high pressures

High temperatures and low pressures

All temperatures and pressures

None of these

The half-life of a radioactive element which has only 1//32 of its original mass left after a lapse of 60 days is:

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12days

10days

22days

36days

A particle executing one dimensional motion, finally comes to rest, what will be the angle between acceleration and displacement during motion:

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0

π

𝜋/2

𝜋/4

The relative permittivity of air is

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1

3.7

7.8

1.0006

The motion of molecules in gases i:

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Orderly

Random

Circular

All of these

Diffraction pattern has also been observed for:

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Proton

Neutron

Hydrogen atom

All of them

The value of universal gas constant R is:

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8.314 J/K mole K

8314 J/ mole K

8.314 J/ mole K

None of these

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

What is the momentum of a photon of light of wavelength 500 nm in kgm/s:

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1.32 × 10−21

1.32 × 10−23

1.32 × 10−25

1.32 × 10−27

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

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Will be different

Will depend on their masses

Will be same

Will depend upon the place of their projection

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

A charge of 2C experiences a force 2000N in a uniform electric field. In this fieldthe potential difference between two points separated by a distance 1cm is

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2V

10V

5V

20V

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

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Isotopes

Isobars

Isomers

Isodiapheres

Interference and diffraction of light confirms its:

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Particle nature

Dual nature

Wave nature

Electromagnetic nature