Electricity & Magnetism MCQs with Answers

Resistivity at a given temperature depends upon?

• A.Length of the conductor
• B.Area of cross-section of the conductor
• C.Nature of material of conductor
• D.Both length and area of cross-section

At which angle between magnetic flux and the vector area is the flux zero?

• A.0 degrees
• B.45 degrees
• C.90 degrees
• D.180 degrees

What is the energy stored in a capacitor if capacitance is 4 μF and voltage is 100 V?

• A.0.01 J
• B.0.04 J
• C.0.02 J
• D.0.08 J

A closed surface contains equal and opposite charges, the net electric flux through the closed surface is?

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

When the output power equals to one-half of the input power, efficiency of the transformer becomes?

• A.25%
• B.50%
• C.75%
• D.100%

Past Paper MCQ

Which is used as an electrode in a dry cell?

• A.Copper
• B.Zinc
• C.Graphite
• D.Iron

Diode can work as _?

• A.Transformer
• B.Amplifier
• C.Oscillator
• D.Rectifier

The electric field at a point due to a point charge is 200 N/C. If a -4 C test charge is placed at that point, then the magnitude of electric field and electric force on it is ?

• A.200 N/C and 800 N
• B.200 N/C and 50 N
• C.800 N/C and 200 N
• D.50 N/C and 800 N

A fuse is placed in series with the circuit to protect against?

• A.High voltage fluctuations
• B.Overloading
• C.Short circuiting
• D.Overheating

If the plates of a charged parallel plate capacitor are pulled away from each other ?

• A.Voltage decreases
• B.Capacitance increases
• C.Voltage remains the same
• D.Voltage increases