Question # 1

The body at rest may have:

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Energy

Momentum

Speed

Velocity

Speedometer of an automobile measures

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Average velocity

Instantaneous velocity

Acceleration

Instantaneous speed

Light of frequency 1.5 times the threshold frequency is incident on a photo sensitive material. If the frequency is halved and intensity is doubled the photo electric current becomes

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Four times

Half

Double

Zero

Bats navigate and find food by:

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Ultrasonic

Echolocation

Refraction

A stone is thrown upwards it returns to ground describing a parabolic path which of the following remains constant:

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Speed of the ball

Kinetic energy of the ball

Vertical component of velocity

) Horizontal component of velocity

The resistance of operational amplifier between inverting and non-inverting terminal is of the order of:

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Few Ohms

Mega Ohms

Few Kilo Ohms

Micro Ohms

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

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Wave nature of particle

Corpuscular nature of wave

Dual nature of particle

All of them

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

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Ampere’s law

Ohm’s law

Coulomb’s law

Faraday’s law65y7uhnb

Torque is necessary for producing.

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angular speed

linear acceleration

angular acceleration

none of these

A radioactive nucleus can emit:

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Electron

𝛼 particles

Positron

Any of these

An electron and a proton are accelerated through the same potential. If their masses are me and mp respectively, then the ratio of their de-Broglie wavelength is:

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1

mp/me

me/mp

The unit of work function is

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eV

Volt

Farad

Herdz

The coulomb’s law is valid for the charges which are:

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Moving and point charges

Stationary and point charges

Moving and non-point charges

Stationary and large size charges

The magnitude of potential barrier for Ge is

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0.7 v

0.3 V

7v

3 v

The angular momentum of a body changes from 30 J-S to 50 J-S in 0.5 sec. The torque acting on it is

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40 N-m

100 N-m

50 N-m

150 N-m

If the stone is thrown up vertically and return to ground, its potential energy is maximum

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during the upward journey

at the maximum height

at the bottom

The example of nuclear fusion is:

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Formation of barium and krypton from uranium

Formation of plutonium -235 from uranium -235

Formation of helium from hydrogen

Formation of water from hydrogen and oxygen

The threshold frequency depends on the nature on:

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Natural frequency

Photosensitive anode

Photosensitive cathode

Photon

Maximum speed of electrons in X-rays tube which is producing X-rays photons of frequency f is

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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 most penetrating radiations out of the following is that of

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𝛾-rays

β-rays

α-particles

X-rays

In which region of the electromagnetic spectrum does the Lyman series of hydrogen atom lie?

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Infrared

Visible

Ultraviolet

X-rays

Davisson and Germer, in their experiment used:

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Nickle crystal

Lead crystal

Graphite crystal

Glass

The momentum of a particle is numerically equal to its K.E. What is the velocity of a particle?

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9 ms^-1

3 ms^-1

2 ms-1

1 ms^-1

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

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5F

0.02F

500F

0.2F

The activity of a radioactive sample is 1.6 curie and half-life is 2.5 days. Its activity after 10 days will be:

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0.8 Curie

0.1Curie

0.4 Curie

0.16 Curie

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

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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

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

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Frictional force

Elastic force

Gravitational force

Centripetal force

A person holds a bucket of weight 60N. He walks 7 m along the horizontal path and then climbs up a vertical distance of 5 m. The work done by the man is:

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300 N-m

420 N-m

720 N-m

none of these

Monochromatic light of wavelength 300 nm is incident normally on a surface of area 4 cm2.

If the intensity of light is 150 mW/m2; the rate at which photon strike the surface:

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2.53 × 1019

7.5 × 1019

9.1 × 1013

2.53 × 1013

The time period of revolution of geostationary satellite is

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1440 minutes

24 minutes

84 minutes

none of these

An engine pumps out 40 kg of water in one second. The water comes out vertically upwards with a velocity of 3ms-1 . What is the power of engine in kilowatt?

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1.2kW

120kW

12kW

1200kW

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

The fundamental frequency in a stretched string is 10 Hz. To double the frequency, the tension in it must be changed to:

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T₂ = 2T₁

T₂ = 4T₁

T₂ = T₁

none of these

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

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 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.

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2 mg

4 mg

6 𝑚g

8 mg

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

A proton and an 𝑎 − 𝒑𝒂𝒓𝒕𝒊𝒄𝒍𝒆 are accelerated through same voltage, the ratio of their de- Broglie wavelength will be:

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1:2

√2: 1

2√2: 1

2:1

A ball takes ‘t’ second to fall from a height 𝒉𝟏 and ‘2t’ second to fall from a height 𝒉𝟐 then h1/h2 is:

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2

4

0.5

0.25

A wave which consists of a single, non-repetitive disturbance is called a

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Continuous wave

Longitudinal wave

Pulse

Transverse wave