Question # 1

In which process the change in internal energy of the system is zero:

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Isochoric process

Isobaric process

Adiabatic process

Isothermal process

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

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Isotopes

Isobars

Isomers

Isodiapheres

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

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

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

Avogadro number is known as number of molecules in:

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One kg of a substance

Unit volume of a substance

One mole of a substance

None of these

An engine pumps up 100 kg of water through a height of 10m in 5s. Given that the efficiency of the engine is 60%, what is the power of the engine? (Take g = 10ms^-2)

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33 kW

3.3kW

0.33kW

0.033kW

Which one is the case when the wavelength is actually changed?

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When source move relative to observer

When observer move relative to source

When observer moves around a stationary source at the center of circle

When the relative displacement between source and observer is zero

The time taken by an engine of power 10 kW to lift a mass of 200 kg to a heightof 40 m is (g + 10ms2)

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2 sec

4 sec

8 sec

16sec

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

For full wave rectification, the minimum number of diodes used is:

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1

2

3

4

The unit Compton wavelength is same as:

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Compton wavelength

Compton frequency

Compton shift

Both (a) & (b)

For a particle in circular motion the centripetal acceleration

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may be more or less than its tangential acceleration

equal to its tangential acceleration a

more than its tangential acceleration

less than its tangential acceleration

The efficiency of a particle heat engine:

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can be 100%

Cannot be 100%

Is always zero

None of these

In a half wave rectifier circuit operating from 50 Hz mains frequency, the fundamental frequency in the ripple would be:

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25 Hz

70.7 Hz

50 Hz

100 Hz

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

The potential difference between head and tail of an "electric eel" can be upto.

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6V

60V

6000V

600V

SI unit of kinetic energy of rotation is

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joule second

joule

joule second

joule meter

A charge is 90C passes through a wire in 1 hour and 15 minutes. Wat is the current in the wire?

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10mA

20mA

15mA

25mA

Electric current is defined as:

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Flow of charges through conductor

Rate of flow of charges through conductor

Flow of electrons

Flow of protons

The ratio of angular speeds of minute hand and hour hand of a watch is:

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1: 12

6: 1

12: 1

1: 6

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

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

To find longest wavelength radiation in Ballmer series, the value of n used is:

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2

3

4

∞

Nuclear fission experiments show that the neutrons the uranium nuclei into two fragment of about the same size. This process is accompanied by the emission of several:

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Protons and positrons

𝛼 −partilces

neutrons

Protons and 𝛼 −partilces

The junction potential for Germanium is;

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3v

0.3 v

7v

0.7 v

. A force "F1" acts on a body through distance "S1" in the direction of motion and does work "W1". Similarly another force "F2" act on same body through distance "S2" but in opposite to the direction of motion and does work "W2". Now if F1 = F2 and S1 = S2 then which statement is correct.

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W1 = W2

W2< W2

W1 > W2

W1 = W2= 0

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

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Oxygen gas

Hydrogen gas

Ideal gas

None of these

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

Which one is the correct express of de-Broglie equation for the length of atoms of mass m at temp? T(k=Boltzmann’s constant):

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The diode charactristics curve is plot between

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I & t

V& t

V& I

None

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 power needed to lift amass of 5000g to height of 1min 2 second is

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2.45 watt

24.5 watt

245 watt

2.45 k watt

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 frequency and work function of an incident photon are n and𝝋𝟎. If f0 is the threshold frequency, then necessary condition for the emission of photo electron is:

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< 𝑓0

𝑓 ≥ 𝑓0

f = 𝑓0/2

None of these

A diode as a rectifier converts:

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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

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:

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2

3

4

6

The fundamental frequency of a closed organ pope is 50 Hz. The frequency ofsecond over tone is

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100hz

150hz

60hz

250hz

Swimming is possible on account of

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1^st law of motion

2^nd law of motion

3^rd law of motion

Newton’s law of Gravitation

The method by which only one half of A.C cycle is converted into direct current is called

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half wave amplification

half wave rectification

Full wave rectification

full wave amplification

Which of the particles, electron, proton and neutron moving with same speed has longest wave length?

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Electron

Proton

Neutron

All have same