Electricity & Magnetism MCQs with Answers

The dielectric constant of water at 18°C is ?

• A.80
• B.72
• C.88
• D.64

A Bloch wave represents the motion of an electron in?

• A.Periodic potential
• B.Uniform electric field
• C.Magnetic field only
• D.Free space

In the electrical companies there must be fire safety to avoid danger, commonly used equipment is ?

• A.Fire blanket
• B.Smoke detector
• C.Fire extinguisher
• D.Sprinkler system

To obtain a p-type semiconductor germanium crystal, it must be doped with foreign atoms whose valency is _?

• A.5
• B.4
• C.3
• D.2

The radiation from a naturally occurring radioactive substance, as seen after deflection by a magnetic field in one direction, are _?

• A.Alpha rays only
• B.Beta rays only
• C.Either alpha or beta rays
• D.Gamma rays only

Past Paper MCQ

Which of the following is a vector quantity?

• A.Electric Current
• B.Speed
• C.Mass
• D.Temperature

In which unit is an analog signal typically measured?

• A.Amperes (A)
• B.Volts (V)
• C.Hertz (Hz)
• D.Watts (W)

When a forward bias is applied to a p-n junction, the concentration of electrons on the p side?

• A.Remains unchanged
• B.Decreases significantly
• C.Increases slightly
• D.Becomes zero

The Fermi level in an intrinsic semiconductor lies?

• A.In the middle of the valence & conduction bands
• B.Near the conduction band
• C.Near the valence band
• D.Inside the conduction band

Which electrolyte is used in a Nickel-Cadmium (Ni-Cd) battery?

• A.Sulfuric acid (H₂SO₄)
• B.Potassium hydroxide (KOH)
• C.Ammonium chloride (NH₄Cl)
• D.Lithium hexafluorophosphate (LiPF₆)