Electricity & Magnetism MCQs with Answers

If potential difference between plates of parallel plate capacitor is doubled then energy stored in it will ?

• A.Be four times
• B.Be doubled
• C.Remain the same
• D.Be halved

What is the primary function of a transformer?

• A.To convert AC to DC
• B.To store electrical charge
• C.To generate electrical energy
• D.To transfer alternating current between circuits

The reverse current in the diode is due to?

• A.Majority carriers
• B.Minority carriers
• C.Both majority and minority carriers
• D.None of these

The voltage _ is used in a vehicle to control the voltage produced at the output of the alternator.

• A.Regulator
• B.Rectifier
• C.Inverter
• D.Transformer

In an ideal transformer ?

• A.Power input is greater than power output
• B.Power input is less than power output
• C.Power input is equal to power output
• D.Power output is zero

The current through a metallic conductor is due to the motion of ?

• A.Neutrons
• B.Positive ions
• C.Protons
• D.Free electrons

A battery of 50V is attached to a series combination of 5 Ω, 10 Ω, 10 Ω resistors. The current in the circuit is ?

• A.2 A
• B.5 A
• C.0.5 A
• D.10 A

An RC low-pass circuit is called ?

• A.Band-pass filter
• B.High-pass filter
• C.Low-pass filter
• D.Amplifier

The correct relation for the charge-to-mass ratio (e/m) of an electron is?

• A.e/m = E²/2B²r
• B.e/m = E/Br
• C.e/m = 2E/B²r
• D.e/m = B²r/2E

Which of the following is an example of an insulator in gaseous form?

• A.Oxygen
• B.Hydrogen
• C.Dry air
• D.Carbon dioxide