Electrical MCQ

What does the yellow triangle with a black lightning bolt symbol indicate?

• Fire hazard

• Electrical hazard

• Biohazard

• Flammable liquid

A red label on a container usually signifies:

• Cold substance

• Harmless gas

• Danger or flammable material

• Low voltage

Which color is typically used for "emergency stop" buttons or switches?

• Green

• Red

• Blue

• Yellow

The label with a skull and crossbones symbol means:

• High voltage

• Irritant

• Toxic or poisonous

• Sharp object

A circuit with dependent sources only (no independent source) has the Thevenin equivalent voltage as:

• Zero

• Depends on load

• Equal to internal EMF

• Infinity

In a symmetrical π-network, the input and output impedance are:

• Different

• Always purely reactive

• Always equal

• Always zero

If a 10 A current flows through a coil having 500 turns and area of 0.2 m², what is the MMF?

• 100 A-T

• 2000 A-T

• 1000 A-T

• 5000 A-T

Relative permeability of a perfect vacuum is

• 1

• 0

• 10

• 100

What happens to hysteresis loss if frequency doubles in a magnetic material?

• Becomes half

• Remains same

• Doubles

• Zero

In Gauss's law for electricity, the total electric flux over a closed surface is equal to:

• Surface area

• Field intensity

• Enclosed charge / ε₀

• Voltage