Electricity & Circuits Quiz

Question 1

What is electric current?

Accepted Answer

The flow of electric charge (electrons) through a conductor

Answer

The energy stored in a battery

Answer

The resistance of a wire

Answer

The voltage across a component

Question 2

What is the SI unit of electrical resistance?

Accepted Answer

Ohm (Ω)

Answer

Volt (V)

Answer

Ampere (A)

Answer

Watt (W)

Question 3

State Ohm's Law.

Accepted Answer

V = I × R

Answer

P = I × V

Answer

R = V + I

Answer

I = V + R

Question 4

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

Accepted Answer

3 A

Answer

48 A

Answer

8 A

Answer

0.33 A

Question 5

In a series circuit with two resistors, how does the total resistance compare to the individual resistors?

Accepted Answer

Total resistance is the sum of all resistors

Answer

Total resistance is less than either individual resistor

Answer

Total resistance equals the larger resistor only

Answer

Total resistance is the product of all resistors

Question 6

In a parallel circuit with two identical resistors of 10 Ω each, what is the total resistance?

Accepted Answer

5 Ω

Answer

20 Ω

Answer

10 Ω

Answer

2.5 Ω

Question 7

What does a voltmeter measure and how is it connected?

Accepted Answer

Voltage; connected in parallel across a component

Answer

Current; connected in series

Answer

Resistance; connected anywhere

Answer

Power; connected in series

Question 8

What is the formula for electrical power?

Accepted Answer

P = V × I

Answer

P = V/I

Answer

P = I²/R

Answer

P = V² × I

Question 9

What is the difference between AC and DC electricity?

Accepted Answer

DC flows in one direction; AC periodically reverses direction

Answer

AC flows in one direction; DC alternates direction

Answer

AC is used in batteries; DC is used in homes

Answer

There is no practical difference

Question 10

What is potential difference (voltage)?

Accepted Answer

The energy transferred per unit charge between two points

Answer

The number of electrons in a wire

Answer

The speed of electrons in a conductor

Answer

The total resistance in a circuit

Question 11

A 1200 W kettle is used for 0.1 hours. How many kilowatt-hours of energy does it use?

Accepted Answer

0.12 kWh

Answer

120 kWh

Answer

12 kWh

Answer

1.2 kWh

Question 12

What is an LED?

Accepted Answer

A Light Emitting Diode — a semiconductor component that emits light when current flows through it

Answer

A device that converts light into electricity

Answer

A type of resistor

Answer

A device that stores electrical charge

Question 13

In a series circuit, if one bulb blows, what happens to the other bulbs?

Accepted Answer

They all go out

Answer

They glow brighter

Answer

They stay the same

Answer

They flicker

Question 14

What is the charge on an electron?

Accepted Answer

Negative

Answer

Positive

Answer

Neutral

Answer

Variable

Question 15

What is a superconductor?

Accepted Answer

A material that conducts electricity with zero resistance below a critical temperature

Answer

A very good conductor like copper

Answer

A conductor that resists very high currents

Answer

An insulator at low temperatures

Question 16

What is the function of a fuse in an electrical circuit?

Accepted Answer

To melt and break the circuit if current is too high, preventing fire or damage

Answer

To increase voltage

Answer

To store charge

Answer

To reduce resistance

Question 17

Two resistors of 6 Ω and 3 Ω are connected in parallel. What is the total resistance?

Accepted Answer

2 Ω

Answer

9 Ω

Answer

4.5 Ω

Answer

18 Ω

Question 18

What is the relationship between charge (Q), current (I), and time (t)?

Accepted Answer

Q = I × t

Answer

Q = I/t

Answer

I = Q × t

Answer

t = Q × I

Question 19

Which material is the best electrical conductor?

Accepted Answer

Silver

Answer

Glass

Answer

Rubber

Answer

Plastic

Question 20

What is the National Grid?

Accepted Answer

A system of pylons, cables, and transformers that distributes electricity from power stations to homes and businesses

Answer

A network of gas pipelines

Answer

A type of solar power grid

Answer

The UK's broadband network