WorksheetsElectrical Supply Quiz
Total questions: 15
Worksheet time: 8mins
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.
What is more likely to happen with the phases in a circuit?
All phases will differ slightly.
All phases will be perfectly balanced.
All phases will be grounded.
All phases will be disconnected.
How can the neutral current be established?
By entering all values into a formula.
By measuring the voltage.
By using a voltmeter.
By calculating the resistance.
What geometric shape is used to establish the neutral current?
Equilateral triangle
Square
Circle
Rectangle
What is the result if the phases are different and unbalanced?
There will be a gap in the triangle.
The circuit will short circuit.
The voltage will drop to zero.
The current will double.
What is the likely outcome if phases are not balanced?
Phases will differ slightly.
Phases will be perfectly balanced.
Phases will be grounded.
Phases will be disconnected.
