Online Test

Question # 1

The wave motion set up in any medium depends upon:

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Elasticity

Inertia

Density

All of these

When the observer is moving towards the source at rest the apparent frequency will be

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Increased

Decreased

Not changed

None of these

The force between two chares 0.06 m apart is 5N.If each charge is moved towards the other by 0.01 m,then the force between them will become

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7.20 N

11.25 N

22.50 N

45.00

The consumption of energy by a 60 watt bulb in 2 sec is

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60 J

120 J

30 J

0.2 J

When a silicon crystal is doped with a pentavalent element, then the atom of the pentavalent element is known as

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acceptor

donor

either of them

none of them

The unit of conductance of material is

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Mho

Siemen

Ohm

All of them

A wave with higher frequency will have

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Lower speed

Lower time period

Shorter wavelegth

Greater amplitude

If an aeroplane moves away the radar, the wavelength reflected from it would be

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Larger

Shorter

Remains the same

None of these

The generated emf in a A.C. generator is maximum when the magnetic field B and plane of coil are

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at an angle of 60°

perpendicular

parallel

none of these

A p-n junction diode cannot be used for

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Verification

Amplification

Obtaining right radiation

Detecting light intensity

In case when there is not total displacement and average velocity, then the motion is described by

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Variable velocity

Instantaneous velocity

Initial velocity

None of these

Angle between ray of light and the corresponding wave front is

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10°

60°

90°

120°

0.1 Kg mass will be equivalent to the energy

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9 x 10¹⁵J

5 x 10⁸J

6 x 10¹⁶J

9 x 10^-16J

The absolute temperature for an ideal gas is

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directly proportional ot the rotational K.E of gas molecules

directly proportional to the vibrational K.E of gas molecules

directly proportional to the average translational K.E of gas molecules

directly proportional to the P.E of gas molecules

1 year = ______.

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3.1536 x 10⁷s

3.1536 x 10^-7s

3.1536 x 10¹⁰s

3.1536 x 10^-10s

A capacitor is charged with a battery and then it is disconnected A slab of dielectric is now inserted between the plates then

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The charge in the plates reduces and potential difference increase

Potential difference between the plates increases stored energy decreases and charge remains the same

Potential difference between the plates decreases,stored energy decreases and charge remains unchanged

None of the above

The magnetic field at the centre of a current carrying circular loop is B. If the radius of hte loop is doubled keeping the current the same, the magnitude filed at the centre of the loop would be

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B/4

B/2

2B

4B

Age of the Universe is

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5 × 10¹⁵ sec

5 × 10¹⁷ sec

5 × 10¹⁹ sec

None of these

The energy of the oscillation comes from the

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Applied force

Driving source

Starting source

None of these

The acceleration of the rocket is

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What temperature of a conductor increase the resistance:

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Increases

Remains same

First increases then increases

None of the above

The mass 'm' of a body moving at 0.8 c (whose rest mass is m₀) becomes

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2 m₀

1.67 m₀

0.67 m₀

2.67 m₀

Light waves are:

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Transverse waves

Longitudinal waves

Compressional waves

None of them

The speed of sound waves depends upon the

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compressibility of the medium

inertia of the medium

both of them

none of them

What is the internal energy of an object?

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it is the energy associated with the object's movement as a whole

it is the energy associated with the random movement of the molecules in the object

it is the energy due to the attractions between the molecules within the object

It is the sum of all the microscopic potential and kinetic energies of the molecules

First law of thermodynamics tells us that heat energy can be converted into work which is

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Equivalent

Greater

Lower

None of these

The control rods in the atomic reactor helps to absorb the fast neutrons are

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Boron

Cadmium

Lead

All of these

The resolution of microscope depends on objective's

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Focal length

Material

Diameter

None of these

Using OP-Amp as an inverting amplifier, this non-inverting terminal has potential

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Low

High

Zero

None of these

The escape velocity of Neptune in Kms^-1

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20.26

24.03

25.4

25.6

Amorphous solids are more like

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crystalline solids

polymeric solids

glassy solids

any one of them

Electron microscope makes practical use of the

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Particle nature of electron

Wave nature of electron

Dual nature of electron

Neither particle nor wave nature of electron

The half life of uranium -238 is

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1.67 x 10⁸years

3.3 x 10⁹years

4.5 x 10⁸years

4.5 x 10⁹years

One thousand watts of electric power is transmitted to a device by means of two wires each of which has resistance of 2 ohm if the resulting potential difference across the device is 100 volts the potential difference across the source supplying power is

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240 V

100 V

50 V

200 V

Who gave the idea of light as wave ?

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Newton

Huygen

Thomos Young

Bragg

Which of the following is not an advantage of X-ray imaging of internal body structures over invasive diagnosic techniques?

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less traumatic for patient

presents a much smaller risk than surgery

is more costly

none of them

CRO is used to find

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Phase difference between A-C voltages

Frequency and Time period of A-C voltages

Peak and rms value of alternating voltage

All of these

Which of the following gate performs the operation of inversion or complementation

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AND gate

OR gate

NOT gate

NAND gate

Assuming the earth to be a sphere of radius 6400 km. What is the value of acceleration due to gravity at a height of 800 km above the surface of the earth ?

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5.35 ms^-1

6.35 ms^-2

7.35 ms^-2

8.35 ms^-2

In colour printing, the entire range of colours uses just

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Three colours

Four colours

Five colours

None of these

A 500 kg car takes a round turn of radius 0 m with a velocity of 36 km/h.The centripetal force is

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250 N

750 N

1000 N

1200 n