Online Test

Question # 1

During adiabatic compression of a gas,its temperature

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Falls

Rises

Remains constant

Becomes zero

Laser beam can be used for

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Wilding of detached retinas

Destroy tissues in a localized area

Sealed off capillaries for prevention of disease

All of them

Inner shell transition in X-Rays takes place in

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Lighter elements

Medium element

Heavy elements

None of these

Which one of the following is scalar?

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Magnetic field

Flux density

Magnetic flux

Induced emf.

Which of the following pairs represent units of the same physical quantity

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Kelvin and joule

Kelvin and calorie

Newton and calorie

Joule and calorie

When a charge particles is moving in magnetic field the magnetic force acts on it changes

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Magnitude of its velocity

Direction of its velocity

Both magnitude and direction

Neither magnitude nor direction

When a body moves in a circle its projection performs what type of motion?

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Circular Motion

Angular Motion

Simple Harmonic Motion

Rectilinear Motion

According to Huygen's principle, every point of a wavefront may be considered as a source of

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primary wavelets

secondary wavelets

either of them

both of them

When a mass 'm' is pulled slowly, the spring stretched by an amount X₀ then the average force would be

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F = KX₀

F = 1/2 KX₀

F = 1/2 KX₀²

F = 1/4 KX₀²

Why do real gases deviate from ideal bahaviour?

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Real gases consist of a very small number of molecules within a given volume

Real gasses have intermolecular forces

Molecules of real gases are not in rapid, random motion

None of them

Optically active substance are those substance which

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Produce polarization of polarized light

Rotate the plane of polarization of polarized light

Produce double refraction

Both a and b

Kirchhoff's first rule is also known as

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Kirchhoff's point rule

Law of conservation of charge

Kirchhoff's current rule

All of them

When the temperature of source and sink of heat engine become equal than efficiency of heat engine will

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Maximum

Minimum

Negative

Zero

In order to get interference using two light rays:

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The sources should be monochromatic and coherent

The sources should have the same frequency

Superposition should be linear

All of these

In carbon colour coded resistances the fourth silver band indicates the tolerance is

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± 5 %

±10 %

± 20 %

None of these

A 1500 kg car has its velocity reduced from 20 ms^-1 to 15 ms^-1 in 3.0 S. How large was the average retarding force

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- 4.5 KN

- 2.5 KN

- 3.7 KN

- 4.3 KN

The temperature at which the speed of sound becomes double as was at 27°C is

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273°C

0°C

927°C

1027°C

Electromotive force is not a force and is measured in

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Coulomb

Ampere

Volt

None of these

At the temperature a body emits radiation which is principally

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of long wavelengths and in the visible region

of long wavelengths in the invisible infrared region

of short wavelength in invisible ultraviolet region

none of them

Which of the following sets of concurrent forces may be in equilibrium?

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F₁ - 3 N,F₂ - 5 N,F₃ = 6 N

F₁ - 3 N,F₂ - 5 N,F₃ = 15 N

F₁ - 3 N,F₂ - 5 N,F₃ = 1 N

F₁ - 3 N,F₂ - 5 N,F₃ = 9 N

The limit up to which the stress is directly proportional to strain is called

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Elastic limit

Proportional limit

Breaking limit

Ultimate tensile limit

The defection in moving coil galvanometer falls from 50 division to 10 division,when a shunt of 12 Ω is applied the resistance of galvanometer coil is

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24 Ω

12 Ω

50 Ω

48 Ω

The resistors used in most of electronic device are made of

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gold

copper

rubber

carbon

A pipe has a length of 1m. Determine the fundamental frequency when one end of the pipe is closed. Speed of air is 340 ms

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80 Hz

82 Hz

84 Hz

85 Hz

The heart of machine is

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Lamp and camera unit

Aluminium drum

Charging unit

All of them

The energy supplied to unit charge by the cell is defined as

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conductivity

resistivity

emf (E)

potential difference

Viscosity of gas with increase in temperature

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Decreases

Increases

No change

All

When a current-carrying conductor of length 'L' is placed in magnetic field B, this experience a force

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F = IL/B

F = ILB Sinθ

F = BI Sinθ

F = ILB Cosθ

With two up quarks and one down quark, which of the following can be made?

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electron

proton

photon

neutron

When the density is constant for the steady flow of incompressible fluid equation of continuity becomes

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ρ₁A₁V₁ = ρ₂A₂V₂

ρ₁m₁A₁V₁ = ρ₁m₁A₂V₂

A₁V₁ = A₂V₂

None of these

The basic circuit element in D.C. circuit is a

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Capacitor

Resistor

Inductance

None of these

The minimum frequency below which no electrons are emitted is called

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Lowest frequency

Threshold frequency

Synchronized frequency

None of these

The base of the transistor is very thin of the order of

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10^-2 m

10^-4 m

10^-6 m

10^-8 m

At resonance if the capacitance of the capacitor is doubled in resonance series circuit than the resonance frequency is

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Also doubled

Become four times

Decreases by √2-times

Increases by √2 times

Gravity performs zero work when body moves

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Vertically

Horizontally

At angle 60° with vertical

At angel 60° with horizontal

Semiconductors, like Ge or Si at room temperature becomes a

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Semiconductor

Conductor

Insulator

None of these

In which of the following detector the size of the pulse in independent of the energy of the particle

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GM counter

Solid state detector

Both a & b

None

When a nuclear emits an alpha radiation/particles its atomic number drops by

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1

2

3

4

Ohms is the unit of

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current

capacitance

energy

resistance

The relation between Boltzmann's constant K, gas constant R and Avogadro's number is N_Ais

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K = N_A/R

K = RN_A

K = R/N_A

K = PV/NT

If the distance of separation between two chares is increased,the electrical potential energy of the system will

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Increase

Decrease

May increase or decrease

Remain the same