ECAT Pre Computer Science Physics MCQ Test With Answer for Full Book

According to the equation of continuity, when water falls from the tap, it's speed increases and its cross-sectional area

• decreases A
• increases B
• becomes zero C
• none of them D

The appearance of colours in the soap (or oil) film results from

• Dispersion A
• Interference B
• Reflection C
• Refraction D

Fluids resist force, This property is called

• Stiffness A
• Strength B
• Ductility C
• Elasticity D

A virtual image is formed when object is placed:

• Within focal length of a convex lens A
• Near the focal point of a concave lens B
• Both A and B C
• Away from 2F of a convex lens D

When a body moves against the force of friction on a horizontal plane, the work done by the body is:

• Positive A
• Negative B
• Zero C
• None of these D

Which one of the following is dimensionless:

• Acceleration A
• Velocity B
• Density C
• Angle D

The temperature at which the vibrations become so great that structure of the Crystal breaks up, is called:

• Critical temparature A
• Temperature of vaporization B
• Melting point C
• Both (A) and (C) D
• Both (A) and (B) E

Phenomenon of radioactivity is due to disintegration of

• nucleus A
• neutron B
• proton C
• molecule D

Total number of turns on 0.15 m length solenoid is 300. the value of n is:

• Greater than 300 A
• Smaller than 300 B
• Equal to 300 C
• Any of (A) or (B) D
• Any of (A) or(C) E

The loudness and pitch of a sound note depends on

• Intensity and velocity A
• Frequency and velocity B
• Intensity and frequency C
• Frequency and number of harmonic D

If the external driving force is periodic with a period compareable to the natural period of the oscillator, then we get

• diffraction A
• beat B
• interference C
• resonance D

The restoring force is always directed towards:

• Rest position A
• Equilibrium position B
• Mean position C
• All of them D

Step up transformer has a transformation ratio of 3:2. What is the voltage in secondary, if voltage in primary is 30V:

• 45 V A
• 15 V B
• 90 V C
• 300 V D

The work done by the system on its environment is considered as

• positive A
• negative B
• zero C
• any one of them D

The SI unit of magnetic induction is

• Gauses A
• Tesla B
• Weber C
• Weber² D

Watt x second is unit of:

• Force A
• Work B
• Power C
• None of these D

Which is modified form of galvanometer

• potentiometer A
• battery B
• voltmeter C
• slide wire bridge D

The speed of randomly moving electrons depends upon

• pressure A
• volume B
• temperature C
• mass D

Liquids and gasses have

• zero viscosity A
• non-zero viscosity B
• very large viscosity C
• very small viscosity D

A car is turning around a corner at 10 m/sec as it travels along an arc of circle. If value of centripetal acceleration is 10 m/sec²in this case, find radius of the circular path:

• 1 m A
• 5 m B
• 10 m C
• 15 m D

In a transistor, if the central region is p-type then this type of transistor is known as

• p-n-p transistor A
• n-p-n transistor B
• either of these C
• none of these D

The temperature scale approved in SI units is:

• Celsius scale A
• Kelvin scale B
• Fehrenheit scale C
• None of these D

For inducting emf in a coil the basic requirement is that:

• Flux should link the coil A
• Change in flux should link the coil B
• Coil should form a closed loop C
• Both B and C are true D

• 5μF A
• 10μF B
• 3μF C
• 6μF D

The kinetic energy of one molecule of a gas at normal temperature and pressure will be (k = 8.31 J/mole K) :

• 1.7 x 10³J A
• 10.2 x 10³J B
• 3..4 x 10³J C
• 6.8 x 10³J D

When certain area A is held parallel to the field lines, then:

• No lines cross this area

  A

• Maximum lines pass through this area

  B

• The number of lines are between zero and maximum

  C

• Both (A) and (B) correct

  D

• None of these

  E

A railway engine (mass 10⁴kg) is moving with a speed of 73 km/h. The force which should be applied to bring it to rest over a distance of 20 m is

• 3,600 N A
• 7,200 N B
• 10,000 N C
• 100,000 N D

Blomass includes:

• Crop residue A
• Natural vegetation B
• Animal dung C
• All of these D

The rear wheels of an automobile are rotating with an angular velocity of 14 rev/sec which is reduced to 38 rad/sec in 5 second when brakes are applied. Its angular acceleration is:

• 5 rad/sec² A
• -10 rev/sec² B
• -10 rad/sec² C
• -5 rev/sec² D

A body moving along the circumference of a circle of radius R completes one revolution. The radius of a covered path to the angle subtended at the centre is:

• Radius of the circle A
• Twice the radius B
• Thrice the radius C
• None of these D