Circuit Photos

Question 1

What is a circuit diagram?

Answer 1

A visual representation showing how the components in a circuit are connected together

Each component has its own symbol, which must be recognized to avoid confusion.

Question 2

What is the difference between a battery and a cell?

Answer 2

A cell is a single unit that provides electric power, while a battery consists of two or more cells connected together.

Question 3

What determines the size of an electric current?

Answer 3

The rate of flow of electric charge, which is the number of electrons passing through a component each second.

Question 4

How is electric current measured?

Answer 4

In amperes (A), sometimes abbreviated as ‘amps’.

Question 5

Fill in the blank: An electric current of 1 ampere is a rate of flow of charge of _______ per second.

Answer 5

1 coulomb

Question 6

What is the equation relating charge flow, current, and time?

Answer 6

Q = I × t

Where Q is charge (coulombs), I is current (amperes), and t is time (seconds).

Question 7

What is the role of a switch in an electric circuit?

Answer 7

To enable the current in a circuit to be switched on or off.

Question 8

What does a diode do?

Answer 8

Allows current to flow in one direction only.

Question 9

What is a light-emitting diode (LED)?

Answer 9

A diode that emits light when a current passes through it.

Question 10

What is the function of an ammeter?

Answer 10

To measure electric current.

Question 11

What is a fuse designed to do?

Answer 11

To melt and break the circuit if the current exceeds a certain amount.

Question 12

What is the purpose of a variable resistor?

Answer 12

To allow the current in a circuit to be varied.

Question 13

What does a voltmeter measure?

Answer 13

Potential difference (voltage).

Question 14

True or False: The current at any point in a single closed loop circuit is the same as the current at any other point.

Answer 14

True

Question 15

What is electric charge measured in?

Answer 15

Coulombs (C).

Question 16

What happens to the brightness of a bulb when the slider of a variable resistor is moved?

Answer 16

The brightness changes depending on the amount of current flowing through the bulb.

Question 17

What happens if a diode is incorrectly placed in a circuit?

Answer 17

It can damage components, such as a portable radio, if batteries are inserted the wrong way.

Question 18

How do you calculate the charge passing through a lamp if the current is 0.25 A for 60 seconds?

Answer 18

Charge, Q = I × t = 0.25 A × 60 s = 15 C

Question 19

What is the significance of the positive terminal symbol on a cell?

Answer 19

Indicates the positive terminal of the cell, which is essential for correct circuit assembly.

Question 20

Fill in the blank: An electric current is a flow of _______.

Answer 20

Charge

Question 21

What is the effect of moving the slider on a variable resistor towards one side?

Answer 21

It alters the amount of current flowing through the circuit.

Question 22

What is the main purpose of an electric heater in a circuit?

Answer 22

To transfer energy from an electric current to heat the surroundings.

Question 23

What is the historical significance of the direction of current flow in circuits?

Answer 23

The convention shows current flow from positive to negative, despite electrons moving from negative to positive.

Question 24

What occurs when an electric current flows through a bulb?

Answer 24

It emits light as a signal indicating current presence.

Question 25

What is the relationship between the number of electrons and the size of the current?

Answer 25

A larger number of electrons passing through a component each second results in a larger current.