Topic 9: Electricity and Circuits

Question 1

What is the formula linking charge, current, and time?

Answer 1

Charge = Current × Time (Q = It)

This formula shows the relationship between electric charge, current, and time.

Question 2

What is the unit of charge?

Answer 2

Coulomb (C)

The coulomb is the standard unit of electric charge in the International System of Units (SI).

Question 3

What is Ohm’s Law?

Answer 3

Voltage = Current × Resistance (V = IR)

Ohm’s Law describes the relationship between voltage, current, and resistance in an electrical circuit.

Question 4

What is the difference between a series and a parallel circuit?

Answer 4

In a series circuit, components share the same current. In a parallel circuit, each branch gets the full voltage.

This distinction affects how voltage and current behave in different circuit configurations.

Question 5

How do you calculate electrical power?

Answer 5

Power = Voltage × Current (P = VI)

This formula is used to determine the power consumed or produced in an electrical circuit.

Question 6

What is the purpose of a resistor in a circuit?

Answer 6

To limit the current.

Resistors are essential components that control the flow of current in a circuit.

Question 7

What happens to the total resistance in a series circuit?

Answer 7

It is the sum of all individual resistances.

The total resistance increases as more resistors are added in series.

Question 8

What happens to the total resistance in a parallel circuit?

Answer 8

It decreases as more resistors are added.

This occurs because additional paths for current flow reduce the overall resistance.

Question 9

What is a diode?

Answer 9

A component that allows current to flow in only one direction.

Diodes are often used in rectifiers and to protect circuits from reverse polarity.

Question 10

What is the function of a fuse?

Answer 10

To break the circuit if the current is too high, protecting the components.

Fuses are safety devices that prevent damage from excessive current flow.