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 offered when measuring across a phase to neutral?

• 110V

• 230V

• 400V

• 500V

In a delta connection, what happens to the voltage?

• It doubles

• It halves

• It does not change

• It triples

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

What is the typical current supply for a domestic property?

• 50A

• 75A

• 100A

• 150A

Why is a 400V three-phase supply required for large commercial outlets?

• To reduce voltage

• To meet greater current demand

• To increase voltage

• To decrease current demand

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

• Reduces the need for a neutral cable

• Balances each phase with the same loading

• Increases the need for more conductors

• Decreases the efficiency of the system

What allows unbalanced loads to operate safely in a three-phase system?

• The phase cable

• The line cable

• The neutral cable

• The ground cable

What happens to the unbalanced current without a balancing facility?

• It circulates in the circuit.

• It is grounded.

• 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 three phases must be balanced and have an equal amount of current.

• The circuit must be open.

• The voltage must be zero.

• The resistance must be infinite.