Question 1

What is electric current?

Accepted Answer

Electric current is the flow of electric charge (electrons) through a conductor, measured in amperes (A).

Question 2

What is voltage?

Accepted Answer

Voltage is the electrical potential difference that drives current through a circuit, measured in volts (V).

Question 3

What is resistance?

Accepted Answer

Resistance is the opposition to the flow of electric current, measured in ohms (Ω).

Question 4

What is a conductor? Give two examples.

Accepted Answer

A conductor is a material that allows electric current to flow easily. Examples include copper wire and aluminum foil.

Question 5

State Ohm's Law.

Accepted Answer

Ohm's Law states that V = I × R, where V is voltage, I is current, and R is resistance.

Question 6

What happens to current if resistance increases (voltage stays the same)?

Accepted Answer

If resistance increases and voltage stays the same, current decreases (I = V/R).

Question 7

A circuit has a voltage of 12V and a resistance of 4Ω. What is the current?

Accepted Answer

I = V/R = 12/4 = 3 amperes (A).

Question 8

If current is 2A and resistance is 5Ω, what is the voltage?

Accepted Answer

V = I × R = 2 × 5 = 10 volts (V).

Question 9

What is a series circuit?

Accepted Answer

A series circuit is one where all components are connected in a single path, so the same current flows through every component.

Question 10

What happens to the other bulbs in a series circuit if one bulb burns out?

Accepted Answer

All other bulbs go out because the circuit is broken — there is only one path for current to flow.

Question 11

How is total resistance calculated in a series circuit?

Accepted Answer

Total resistance in a series circuit is the sum of all individual resistances: R_total = R1 + R2 + R3 + ...

Question 12

How does voltage distribute across components in a series circuit?

Accepted Answer

Voltage is divided (shared) among all components in a series circuit; each component gets a portion of the total voltage.

Question 13

What is a parallel circuit?

Accepted Answer

A parallel circuit has multiple paths for current to flow; each component is connected across the same two points (same voltage).

Question 14

What happens to the other bulbs in a parallel circuit if one bulb burns out?

Accepted Answer

The other bulbs remain lit because each branch has its own independent path for current.

Question 15

How is total resistance calculated in a parallel circuit with two resistors?

Accepted Answer

1/R_total = 1/R1 + 1/R2. Total resistance is always less than the smallest individual resistance.

Question 16

Why do household circuits use parallel wiring?

Accepted Answer

Parallel wiring ensures each appliance receives the full voltage and operates independently — turning off one device doesn't affect others.

Question 17

Compare series and parallel circuits: which is safer for home wiring and why?

Accepted Answer

Parallel circuits are safer for home wiring because each device operates at full voltage independently, and a failure in one branch doesn't cut power to the entire circuit.

Question 18

A parallel circuit has two branches with 6Ω and 3Ω resistors and a 9V battery. What is the current through each branch?

Accepted Answer

Branch 1: I = 9/6 = 1.5A. Branch 2: I = 9/3 = 3A. Each branch has the full 9V applied.

Question 19

What is a short circuit and why is it dangerous?

Accepted Answer

A short circuit occurs when current takes an unintended low-resistance path, causing extremely high current flow that can overheat wires, damage components, or start fires.

Circuits Answer Key

Prior Knowledge Questions

Activity A – Ohm's Law

Activity B – Series Circuits

Activity C – Parallel Circuits

Assessment Questions

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