Question # 1

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

A piece of Aluminium (Al) and a piece of Germanium (Ge) are cooled T1 K to T2 K. The resistance of:

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Each of them increases

Each of them decreases

Al increases and Ge decreases

Al decreases and that of Ge increases

Two astronauts in a satellite must have

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Same masses

Same real weights

Same apparent weights

None of these

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

A count rate 240 per minute reduces to 30 counts per min in 1 hour. The half-life of source is:

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20min

60min

80min

90min

If a car moves with a uniform speed of 2 ms-1 in a circle of radius 0.4m. Its angular speed is

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4 rad. s^-1

1.6 rad. s^-1

5 rad. s^-1

2.8 ms^-1

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

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900 Hz

1500 Hz

2100 Hz

600 Hz

Diesel engine coverts ____________ of available heat energy into work.

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20% to 25%

25% to 30%

30% to 35%

35% to 40%

There are two electric bulbs of 40 W and 100 W. They are first connected in series and then in parallel across a source:

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40W bulb will be brighter in series and 100W in parallel

100W bulb will be brighter in series and 40W in parallel

40W bulb will be brighter in both the cares

100W bulb will be brighter in both the cares

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 half-life of a certain element is 3.5 days at STP. If the temperature is doubled and pressure is reduced to half then half-life of the same element will be:

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1.75 days

3.5 days

7 days

14 days

A non-inverting amplifier has infinite input resistance then the voltage gain of noninverting amplifier will be:

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Zero

Infinite

One

100

The junction potential for Germanium is;

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3v

0.3 v

7v

0.7 v

When a particle moves in a circle the angle between it linear velocity and the angular velocity is always

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0°

180°

90°

none of them

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

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10%

45%

50%

75%

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

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1/3g

g

2/3 g

0 m/s2

What happens to the centripetal acceleration of a particle, when its speed is doubled and angular velocity is halved?

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halved

doubled

remain unchanged

becomes four times

A stone is thrown up from the surface of earth when it reaches at maximum height. its total energy is equal to

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mgh

1/2 𝑚𝑣²

zero

2mgh

Two charges of equal magnitudes and at a distance r exert a force F on each other. If the charges are halved and distance between them is doubled, then the new force acting on each charge is:

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F/8

F/4

F/16

4F

An electric field can deflect:

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X-rays

Neutrons

𝛼 −particles

𝛾 −rays

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

A 4 m long string fixed at its ends resonate in 4 segments. The wavelength of the waveis:

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4m

0.5m

2m

0.25 m

Which of the Following bulb will glow Brightest?

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100W

200W

300W

400W

According to boyle's law, volume of a given mass of a gas is

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Inversely proportional mass at constant pressure

Directly proportional to pressure at constant temprerature

Inversely proportional pressure at constant temprature

None of these

If the radius of the circular path of particle going around the circle is doubled without changing its frequency of rotation, then centripetal force on it is.

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doubled

halved

unchanged

quadrupled

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

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

The angular analogue of linear displacement is called

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angular velocity

angular displacement

angular momentum

moment of force

In case of planets the necessary acceleration is provided by

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Gravitational force

coulomb force

frictional force

centripetal force

De-Broglie received the Nobel prize in

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1929

1937

1928

1924

If an electron is accelerated such that its K.E is 4 times of its rest mass energythen thetotal relativistic energy of electrons is about

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5 × 10–12 J

4 × 10–13 J

3 × 10–13 J

6 × 10–12 J

An electric room radiator, which operates at 50V has resistance of 50 Ω. Power of the radiator is approximately:

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100W

50W

450W

1000W

When a gas is compressed:

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Its internal energy decreases

Its temperature decreases

Its temperature increases

None of these

When an electron in an atom goes from a lower to higher its:

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K.E. increases, P.E. decreases

K.E. increases

P.E increases

K.E. decrease, P.E. increases

Electromagnetic waves emitted by hot bodies are called:

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Photoelectrons

Alpha rats

Thermal radiation

None of these

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

In photoelectric effect experiment, stopping potential depend upon

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Intensity of light

Frequency of light

Photoelectric current

Both A and B

In an ideal gas, the molecules have:

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Kinetic energy only

Potential energy only

Both KE and PE

None of these

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

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Energy

Angular momentum

Change

Linear momentum

The product of resistance and conductance of a resistors is equal to:

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1

Conductivity

Resistivity

Zero