Electricity & Magnetism MCQs with Answers

The resistivity of copper is?

• A.5.60 × 10⁻⁸ Ωm
• B.2.82 × 10⁻⁸ Ωm
• C.1.59 × 10⁻⁸ Ωm
• D.1.68 × 10⁻⁸ Ωm

Internal resistance reduces the terminal voltage because it ?

• A.Converts electrical energy into mechanical energy
• B.Increases the EMF of the battery
• C.Reduces the external load resistance
• D.Causes power loss inside the battery

Each plate of a capacitor stores a charge of magnitude 1 mC when a 100 V potential difference is applied. The capacitance is:

• A.10 μF
• B.100 μF
• C.1 μF
• D.0.1 μF

The device which allows only the flow of an alternating current through a circuit is ?

• A.Resistor
• B.Inductor
• C.Capacitor
• D.Transformer

The units of magnetic dipole moment are:

• A.ampere meter²
• B.ampere/meter
• C.ampere/meter²
• D.tesla meter

The RMS value of a sinusoidal current is 10 A. Its maximum value will be?

• A.7.07 A
• B.14.14 A
• C.20 A
• D.10 A

The root mean square value of the alternating current is equal to?

• A.Peak value divided by √2
• B.Peak value multiplied by √2
• C.Constant for all angles
• D.Peak value divided by 2

Lenz's law is the consequence of the law of conservation of?

• A.Momentum
• B.Charge
• C.Energy
• D.Mass

When a small resistance is connected in parallel to a galvanometer, the device becomes a?

• A.Voltmeter
• B.Ohmmeter
• C.Ammeter
• D.Wattmeter

What is the increase in force between two charges if the separation between them is decreased by 50 percent?

• A.Becomes two times
• B.Becomes four times
• C.Becomes eight times
• D.Remains the same