ELECTRICAL & ELECTRONICS QUIZZ

What is the first step you should take when performing maintenance on an electrical installation?

• Turn off the light switches in the area
• Isolate the power supply and lock out the circuit
• Wear rubber gloves
• Check voltage with a multimeter

A circuit breaker keeps tripping in a residential installation. Which of the following is the most likely cause?

• A disconnected neutral wire
• An overloaded circuit
• A properly functioning circuit
• Low supply voltage

Why is earthing important in an electrical installation?

• It reduces energy consumption
• It improves the lifespan of electrical appliances
• It provides a safe path for fault current to the ground
• It increases the circuit's resistance

What is the function of a capacitor in an electrical circuit?

• Convert AC to DC
• Store and release electrical energy
• Reduce electrical noise
• Control the circuit’s current flow

If a circuit supplies a total load of 3000W at 230V, what is the current drawn by the circuit?

• 10.87 A
• 12.67 A
• 13.04 A
• 15.65 A

Which of the following measures can improve energy efficiency in electrical installations?

• Installing oversized cables
• Using LED lighting instead of incandescent lamps
• Increasing circuit voltage
• Reducing the insulation of conductors

If all the lights in a house go off suddenly, but the appliances connected to sockets are working fine, what is the most probable cause?

• Main fuse is blown.
• Fault in the lighting circuit.
• Neutral wire is disconnected.
• Overloading of the circuit.

Which of the following switches would you use for controlling a light from two different locations?

• Single pole switch
• Double pole switch
• Two-way switch
• Dimmer switch

A three-phase induction motor fails to start, but the contactor engages. What is the most probable cause?

• Overload relay tripped
• One phase of the supply is missing
• Motor windings are open
• Incorrect contactor wiring

Which of the following components is used to protect a motor from overload conditions?

• Circuit breaker
• Fuse
• Overload relay
• Contactor