Unit 4 Sem B Review

What is Ohm's Law and how is it applied in circuits?

• Ohm's Law is V = I * R, used to relate voltage, current, and resistance in circuits.

• Ohm's Law only applies to alternating current (AC) circuits.

• Ohm's Law states that current is equal to voltage divided by resistance.

• Ohm's Law is used to calculate power in a circuit as P = V + I.

Calculate the current flowing through a circuit with a voltage of 12V and a resistance of 4Ω.

• 4A

• 2A

• 6A

• 3A

If a circuit has a power of 60W and a voltage of 120V, what is the current?

• 1A

• 0.25A

• 2A

• 0.5A

In a series circuit with three resistors of 2Ω, 3Ω, and 5Ω, what is the total resistance?

• 12Ω

• 10Ω

• 6Ω

• 8Ω

What happens to the total resistance in a series circuit if more resistors are added?

• The total resistance increases.

• The total resistance remains the same.

• The total resistance decreases.

• The total resistance fluctuates randomly.

In a parallel circuit with two resistors of 6Ω and 3Ω, what is the total resistance?

• 1Ω

• 4Ω

• 9Ω

• 2Ω

How does the voltage across each component in a parallel circuit compare?

• The voltage is zero across all components.

• The voltage is higher for some components than others.

• The voltage across each component in a parallel circuit is the same.

• The voltage varies across each component.

What is the difference between AC and DC power?

• AC power is generated by batteries, while DC power is generated by generators.

• AC power alternates direction, while DC power flows in one direction.

• DC power is used in household outlets, while AC power is not.

• AC power is more efficient than DC power.

List one advantage of using AC power over DC power.

• Easier voltage transformation for efficient long-distance transmission.

• Simpler circuit design for small devices.

• Lower energy loss in transmission.

• More stable voltage output.

What is the principle of operation of an electric motor?

• An electric motor transforms mechanical energy into electrical energy.

• An electric motor generates heat from mechanical energy.

• An electric motor converts electrical energy into mechanical energy using electromagnetic principles.

• An electric motor uses only chemical reactions to operate.