Electrical Supply Quiz

What type of supply can star-connected systems feed?

• Only domestic properties

• Only commercial properties

• Both domestic and commercial properties

• Neither domestic nor commercial properties

What is the single-phase supply voltage when measuring across a phase to neutral?

• 110V

• 230V

• 400V

• 500V

What is the three-phase supply voltage when measuring across any two phases?

• 110V

• 230V

• 400V

• 500V

In a star connection, what happens to the current?

• It increases

• It decreases

• It does not change

• It fluctuates

In a delta connection, how is the line current related to the phase current?

• Equal to the phase current

• Twice the phase current

• √3 times the phase current

• Half the phase current

Why is a single-phase supply insufficient for large commercial outlets?

• It is too expensive

• It cannot meet the current demand

• It is too complex

• It is not reliable

What is the benefit of distributing loads in a three-phase supply?

• Reduces cost

• Balances each phase with the same loading

• Increases power

• Decreases efficiency

What is a consequence of not balancing all three phases?

• Increased efficiency

• Reduced power

• Small variations in current

• No effect

What happens to the unbalanced current if there is no facility to manage it?

• It dissipates into the ground.

• It circulates in the circuit.

• It is stored in a capacitor.

• It is converted to heat.

What condition must be met for no current to flow in the neutral conductor?

• All phases must be unbalanced.

• All phases must have different currents.

• All phases must be balanced with equal current.

• All phases must be grounded.