Topic 2 - AC DC

What are the three main components of an electrical circuit?

• Voltage, Current, Resistance
• Voltage, Power, Time
• Current, Resistance, Capacitance
• Voltage, Inductance, Resistance

Answer explanation

Voltage, Current, Resistance

What is the unit of voltage?

• Ampere (A)
• Ohm (Œ©)
• Volt (V)
• Watt (W)

Answer explanation

The unit of voltage is Volt (V).

What is the unit of resistance?

• Ampere (A)
• Ohm (Œ©)
• Volt (V)
• Joule (J)

Answer explanation

The unit of resistance is Ohm (Ω).

What is the unit of current?

• Ampere (A)
• Ohm (Œ©)
• Volt (V)
• Watt (W)

Answer explanation

The unit of current is Ampere (A).

Which of the following is true about Direct Current (DC)?

• It reverses direction periodically.
• It flows in one constant direction.
• It is used in homes and businesses for power supply.
• It is generated by alternators in power plants.

Answer explanation

Direct Current (DC) flows in one constant direction.

Which of the following devices typically uses Direct Current (DC)?

• Refrigerator
• Mobile phone
• Ceiling fan
• Air conditioner

Answer explanation

Mobile phones typically use Direct Current (DC).

What is the direction of current flow in a DC circuit?

• From negative pole to positive pole
• From positive pole to negative pole
• It alternates between positive and negative poles
• It depends on the resistance

Answer explanation

In a DC circuit

Which of the following is true about Alternating Current (AC)?

• It flows in one constant direction.
• It is used in battery-operated devices.
• It reverses direction periodically.
• It has a straight horizontal line waveform.

Answer explanation

Alternating Current (AC) reverses direction periodically.

What is the waveform of Alternating Current (AC)?

• Straight horizontal line
• Sine wave
• Square wave
• Triangular wave

Answer explanation

The waveform of Alternating Current (AC) is a sine wave.

Which of the following is a common source of Alternating Current (AC)?

• Batteries
• Solar cells
• Alternators in power plants
• DC generators

Answer explanation

Alternators in power plants are a common source of Alternating Current (AC).