Electrical Engineering Challenge

What is the main difference between AC and DC?

• AC can only be generated by batteries.

• DC is used in household appliances, while AC is not.

• AC is more efficient than DC.

• AC changes direction periodically; DC flows in one direction.

Name two types of AC machines.

• Synchronous Motor, Induction Motor

• Induction Transformer

• Synchronous Rectifier

• DC Generator

What is the function of a transformer in an AC circuit?

• To filter out noise in the circuit.

• The function of a transformer in an AC circuit is to change voltage levels.

• To convert AC to DC.

• To increase current levels.

Explain the working principle of a DC motor.

• A DC motor uses hydraulic pressure to convert energy into motion.

• A DC motor converts electrical energy into mechanical energy using electromagnetism.

• A DC motor operates solely on alternating current to produce motion.

• A DC motor generates electrical energy from mechanical energy using friction.

What are the advantages of using AC over DC?

• DC is better for long-distance transmission

• Advantages of using AC over DC include efficient long-distance transmission, ease of voltage transformation, and lower costs for generators and motors.

• AC requires more maintenance than DC

• AC is more dangerous than DC

Define the term 'inductance' in electrical circuits.

• Inductance is the resistance of a conductor to the flow of electric current.

• Inductance is the measure of how much voltage is produced by a current in a circuit.

• Inductance is the ability of a conductor to store energy in a magnetic field due to the flow of electric current.

• Inductance refers to the ability of a capacitor to store electric charge.

What is the role of a capacitor in an electronic circuit?

• A capacitor generates electrical energy for circuits.

• A capacitor acts as a resistor to limit current flow.

• A capacitor converts AC to DC voltage.

• A capacitor stores and releases electrical energy, stabilizes voltage, and filters signals in electronic circuits.

List three common semiconductor materials used in electronics.

• Silicon, Germanium, Gallium Arsenide

• Copper

• Aluminum

• Iron

What is the purpose of a diode in a circuit?

• To amplify the current in a circuit.

• To increase the voltage across a circuit.

• To store electrical energy for later use.

• The purpose of a diode in a circuit is to control the direction of current flow.

Explain the difference between NPN and PNP transistors.

• NPN transistors use holes as majority carriers and require a negative base voltage.

• NPN transistors use electrons as majority carriers and require a positive base voltage, while PNP transistors use holes and require a negative base voltage.

• PNP transistors use electrons and require a positive base voltage.

• NPN transistors can operate without a base voltage while PNP transistors cannot.