Year 9 Science · Unit 3 · Lesson 17

Circuit Symbols, Voltage, Current and Resistance

Foundation Worksheet

Name
Date
Class

Learning Goals

Match each term to its definition

Draw a line connecting each circuit component on the left to its correct symbol description and function on the right. Or write the matching letter next to each component.

ComponentYour answerSymbol description & function
CellA. Circle with an "A", measures the rate of current flow in a circuit; connected in series
Bulb (lamp)B. Zigzag line, opposes current flow; used to limit current in a circuit
SwitchC. One long and one short parallel line, provides voltage (electrical "push") to the circuit
ResistorD. Circle with a cross inside, converts electrical energy to light and heat
VoltmeterE. A gap in a line that can be opened or closed, controls whether current flows
AmmeterF. Circle with a "V", measures potential difference; connected in parallel

Fill the gap

Choose the correct word from the word bank to complete each sentence about how electricity flows in a simple torch circuit.

voltage current resistance circuit conductor insulator ampere switch power

A torch contains a battery, a bulb and metal wires that form a closed . The battery provides the electrical "push" that moves electrons through the wires. The metal wires are made of copper, which is a good because it has very low and allows electrons to flow freely. The plastic coating on the wires is an , which prevents electricity from flowing somewhere it should not go. The rate at which electrons flow past a point is called , measured in the unit .

1. Define voltage and current in your own words. Give the unit for each quantity.

Recall 2 marks

2. A student removes one wire from a simple circuit containing a battery, switch and bulb. Explain why the bulb goes out immediately, using the terms "complete circuit" and "current" in your answer.

Recall 2 marks

Wrap Up

In one sentence, what was the main idea of this lesson?