ECAT Pre Computer Science Chapter 12 MCQ Test With Answer

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

• Increase A
• Decrease B
• May increase or decrease C
• Remain the same D

An electric charge at rest is

• Only an electric field A
• Only a magnetic field B
• Both electric and magnetic fields C
• None of the above D

In a charged capacitor the energy is stored in

• Both in positive and negative charges A
• Positive charges B
• The edges of the capacitor plates C
• The electric field between the plates D

• 5μF A
• 10μF B
• 3μF C
• 6μF D

When an electron is accelerated through a P.D. of an one volt, it will acquire energy equal to

• One joule A
• One erg B
• One electron volt C
• None of these D

Resistance of a conductor is increased, the currant will

• Decrease A
• Increase B
• Remain the same C
• None of these D

The unit of conductance is

• ohm A
• meter B
• mho C
• ohm-meter D

Resistor is a device which convert electric energy to

• Heat energy A
• Chemical energy B
• Elastic energy C
• All of the above D

The charge carriers in gases are

• electrons A
• ions B
• protons C
• ions and electrons D

The resistivity of a substance depends upon the

• length A
• mass B
• area C
• temperature D

An alpha particle is accelerated through a potential difference of 10⁶volt. Its kinetic energy will be

• 1 MeV A
• 2 MeV B
• 4 MeV C
• 8 MeV D

If we increase the distance between two plates of the capacitor, the capacitance will

• Increase A
• Decrease B
• Remain same C
• First increase then decrease D

The colour sequence in a carbon resistor in red, brown, orange and silver. The resistance of the resistor is

• 21 x 10³+ 10% A
• 23 x 10¹+ 10% B
• 21 x 10³+ 5% C
• 12 x 10³+ 5% D

The ratio of the gravitational force F_gto the electrostatic force F_ebetween two electrons at the same distance apart is approximately

• 9.8 A
• 24 x 10¹⁹ B
• 24 x 10⁴² C
• 24 x 10^-44 D

The minimum resistance that can be obtained by connecting 5 resistance of 1/4Ωeach is

• 4/5Ω A
• 5/4Ω B
• 20Ω C
• 0.05 Ω D