Online Test

Question # 1

α-particle emitted with the

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Double energy

Same energy

Half of the energy

None of these

Beta particle are

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hydrogen nuclei

helium nuclei

electrons

photons

Magnetic effect produced due to passage of an electric current through a metallic conductor, utilized in

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Detection of current

Detection of voltage

Creating resistance

None of these

The correct unit of Kinematic viscosity in SI system is

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ra(D) s^-2

m².s^-1

g.s^-2

N .sm^-2

Speed of sound in water at 20°C is

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1214 ms^-1

1343 ms^-1

1483 ms^-1

1567 ms^-1

Which of the following types of cells will be most affected by radioactive rays?

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growing cells

cells that are dividing rapidly

both a and b

cells that divide rarely

How many satellites form the Global positioning system ?

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4

3

20

24

A sine wave is represented by Q the distance between the two particles having same maximum displacement is

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λ/4

λ

2λ

λ/2

Vector A lies in XY plane. For what orientation with both of its rectangular components be negative ?

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I-quadrant

II-quadrant

III-quadrant

None of these

In a PN junction

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High potential at N side and low potential at P side

High potential at P side and low potential at N side

P and N both are at same potential

Undetermined

In p-p chain reaction, the energy given out is

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20.01 MeV

25.7 MeV

26.9 MeV

27.8 MeV

A tall chimney has the advantage/advantages

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Reduce top pressure

Force

Upward flow of smoke

All of these

The value of the input resistance of OP-AMP is if the order of

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few ohms

few hundred ohms

several kilo ohms

several maga ohms

Which of the following is a dimensionless quantity

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Momentum / Acceleration

Volume / Area

Energy / Work

Force / Power

Due to collisions of electrons, with the atoms of conductor, the energy transfer ultimately to the

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Atoms

Electrons

Lattice

All of them

At constant temperature, if the volume of a given mass of a gas is doubled, then the density of gas becomes:

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Double

Remains constant

Half

None of these

The angle between two vectors -2î + 3ĵ + k̂ and î + 2ĵ-4k̂ is:

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0°

90°

180°

None of the above

What is the volume (approx.) of 200 moles of an ideal gas kept at S.T.P?

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5 cm³

50 cm³

5,000 cm³

50,000 cm³

A container of volume 8 x 10⁴m³occupies 20 g oxygen kept at a temperature of 373K.Calculate oxygen pressure

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2.420 kPa

24.20 kPa

242.0kPa

2420kPa

For the monochromatic beam of X-rays, the crystal planes in a lattice act like a

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perfect absorbers

boundary

mirror

none of them

Which of the following is conserved when light waves interfere

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Intensity

Energy

Amplitude

Momentum

In a n-p-n transistor:

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Negative charge moves from collector to base

Negative charge moves from emitter to base

Holes move from base to collector

Holes move from emitter to base

If the mass of the uranium is much greater than the critical mass than

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More neutrons are produced

Rapid chain reaction

Huge explosion is produced

All of them

The ratio of velocity of sound in air at 4 atm pressure and that at 1 atm pressure would be

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1 : 2

4 : 1

1 : 4

2 : 1

In an ideal transformer, the following factors are used

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Input and output power is same

Currents are inversely proportional to voltage

Currents are directly proportional to voltage

None of these

The collection time of electrons and holes of solid state detector is much less than gas filled counters, therefore is counter

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Fast

Low

Very low

None of these

The direction of the angular velocity vector is along

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The tangent to the circular path

The inward radius

The outward radius

The axis of rotation

The sum of positive and negative peak values are usually written as

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P-P value

Negative

Zero

May be positive or negative

If the distance between the plates of a parallel plate condenser of capacity 10 μF is doubled then new capacity will be

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5μF

20 μF

10μF

15 μF

If a stretched string of length 'I' is plucked from its centre, two waves originate, such that

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both will move towards left

both will move towards right

one towards left and other towards right

any one of them

The apparent change in the frequency of sound when an observer is moving away from the source at rest is

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When the waveform of one voltage is increasing and that of second is decreasing and vice versa, then phase difference between these voltages is

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90°

75°

0

180°

For glass-air boundary the critical angle θ_c is

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30^o

41.8^o

42.0^o

44.0^o

The light waves and radio waves differ in

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Speed

Frequency

Wavelength

Both B and C

For the normal operation of the transistor, its

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emitter-base and collector base junctions are forward biased

emitter-base junction is reversed biased and collector base junction is forward biased

emitter-base junction is forward biased and collector base junction is reverse

any one of them

Two waves having same frequency and travelling in the same direction is called

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Diffraction

Interference

Polarization

All of these

At high frequencies of A.C. source in RLC series circuit, the

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Capacitance dominates

Inductance dominates

Resistance dominates

None of these

The speed of the secondary wavelets as mentioned in Huygen's principle is ________ the speed of propagation of the wave itself

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Equal to

Greater than

Smaller than

None of these

Two wires A and B are made of copper both wires are 1m long but wire A is 1mm. thick and wire B is 2mm Thick. The specific resistance

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More for wire A

More for wire B

Same for both wires A and B

Cannot be compared

For an atom having atomic number 'Z' and atomic weight 'A', the number of neutrons in the nucleus is

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A - Z

A

Z

A + Z

The mass density of a nucleus varies with mass number A as

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A²

A

Constant

1/A