Key Circuit Symbols

Question 1

What is the purpose of a circuit diagram?

Answer 1

To show how components are connected together.

Question 2

What is the difference between a battery and a cell?

Answer 2

A cell is a single unit that provides electric charge, 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.

Question 4

How can you calculate the size of an electric current?

Answer 4

Using the equation I = Q/t, where I is current in amperes, Q is charge in coulombs, and t is time in seconds.

Question 5

True or False: An electric current is a flow of charge.

Answer 5

True.

Question 6

What is the symbol for electric current?

Answer 6

I (for current in amperes).

Question 7

Fill in the blank: Electric charge is measured in _______.

Answer 7

coulombs (C).

Question 8

What does a fixed resistor do in a circuit?

Answer 8

Limits the current in a circuit.

Question 9

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

Answer 9

To enable the current to be switched on or off.

Question 10

What does a diode do?

Answer 10

Allows current to flow in one direction only.

Question 11

What does a light-emitting diode (LED) do?

Answer 11

Emits light when a current passes through it.

Question 12

What is an ammeter used for?

Answer 12

To measure electric current.

Question 13

What is the purpose of a variable resistor?

Answer 13

To vary the amount of current flowing through a circuit.

Question 14

What happens when the current through a fuse exceeds a certain amount?

Answer 14

The fuse melts and breaks the circuit.

Question 15

What is a heater designed to do?

Answer 15

Transfer energy from an electric current to heat the surroundings.

Question 16

What is the function of a voltmeter?

Answer 16

To measure potential difference (voltage).

Question 17

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

Answer 17

1 coulomb.

Question 18

In a single closed loop circuit, what can be said about the current at any point?

Answer 18

The current is the same at any point in the circuit.

Question 19

What happens to the brightness of a bulb when the current flowing through it decreases?

Answer 19

The bulb becomes dimmer.

Question 20

What is the direction of conventional current flow in a circuit?

Answer 20

From the positive terminal to the negative terminal.

Question 21

What is the equation for calculating charge flow?

Answer 21

Q = I x t.

Question 22

Describe what happens if you include a diode in a circuit.

Answer 22

It allows current to flow only when connected correctly, preventing damage from incorrect battery placement.

Question 23

What is the agreed symbol for a cell in a circuit diagram?

Answer 23

A long line (positive terminal) and a short line (negative terminal).

Question 24

What does the + symbol next to the long line of a cell indicate?

Answer 24

It indicates the positive terminal of the cell.

Question 25

What is the charge that passes through a lamp if a current of 0.25 A flows for 60 seconds?

Answer 25

15 coulombs.

Question 26

What happens to electrons in a metal when an electric current flows?

Answer 26

Electrons move freely between positively charged metal ions.

Question 27

True or False: The current in a circuit varies depending on the location within the circuit.

Answer 27

False.