ECAT Pre Computer Science Chapter 12 MCQ Test With Answer

If two bulbs one of 60 W and other of 100 W are connected in parallel, then which one of the following will flow more?

• 60 W bulb A
• 100 W bulb B
• Both equally C
• None of these D

The force of repulsion between two point charges is F, when these are at a distance 0.1 m apart. Now the point charges are replaced by sphere of radii 5 cm each having the same charge as that of the respective point charges. The distance between their centre is again kept 0.1 m ; then the force of repulsion will

• Increase A
• Decrease B
• Remain F C
• Become 10F/9 D

A piece of fuse wire melts when a current of 15 ampere flows through it. With this current. If it dissipates 22.5 W, the resistance of fuse wire will be

• Zero A
• 10Ω B
• 1Ω C
• 0.10Ω D

A metal plate of thickness half the separation between the capacitor plates of capacitance C is inserted. The new capacitance is

• C A
• C/2 B
• Zero C
• 2C D

The electric intensity at infinite distance from the point charge will be

• Infinite A
• Positive B
• Zero C
• Negative D

A proton is about 1840 times heavier than an electron. When it is accelerated by a potential difference of 1 KV, its kinetic energy will be

• 1840 KeV A
• 1/1840 KeV B
• 1 KeV C
• 920 KeV D

Coulomb's force between two point charges depends upon

• Magnitude of charges A
• Distance between them B
• Medium in which they are located C
• All of the above D

• 5μF A
• 10μF B
• 3μF C
• 6μF D

Electric generators which convert mechanical energy into

• solar energy A
• thermal energy B
• kinetic energy C
• electrical energy D

If 2.2 kilowatt power is transmitted through a 10 ohm line at 22000 volt, the power loss in the form of heat will be

• 0.1 watt A
• 1 watt B
• 10 watt C
• 100 watt D

The resistance of a conductor does not depend on its

• mass A
• resistivity B
• length C
• cross-sectional area D

Two point charges A and B separated by a distance R attract each other with a force of 12 x 10^-3N. The force between A and B when the charges on them are doubled and distance is halved

• 1.92 N A
• 19.2 N B
• 12 N C
• 0.192 N D

If electric and gravitational force on an electron in a uniform electric field will be

• E=mg/q A
• E=q/mg B
• E=,g/q C
• E=qg/m D

If a charged spherical conductor of radius 10 cm has potential V at a point distance 5 cm from its centre, then the potential at a point distance 15 cm from the centre will be

• 1/3 V A
• 2/3 V B
• 3/2 V C
• 3V D

Specific resistance of a wire depends upon

• Length A
• Cross-section area B
• Mass C
• None D