Physics: Electricity: Circuits and Conductors
Exploring simple circuits, conductors, and insulators
Physics: Electricity: Circuits and Conductors
Exploring simple circuits, conductors, and insulators
Physics - Grade 4-5
- 1
A simple circuit has a battery, two wires, and a light bulb. Explain what must happen for the bulb to light.
Electric current needs an unbroken path to flow.
The bulb will light only if the parts make a complete closed path from one end of the battery, through the bulb, and back to the other end of the battery. - 2
Classify each object as a conductor or an insulator: copper penny, rubber eraser, plastic spoon, steel paper clip.
The copper penny and steel paper clip are conductors because metals usually let electric current flow. The rubber eraser and plastic spoon are insulators because they do not let current flow easily. - 3
A student builds a circuit with a battery, wires, and a bulb, but one wire is not connected to the battery. Will the bulb light? Explain.
Look for a complete loop with no breaks.
The bulb will not light because the circuit is open. Electric current cannot flow through a path that has a gap. - 4
Fill in the blank: A material that allows electric current to flow through it easily is called a ____.
A material that allows electric current to flow through it easily is called a conductor. - 5
Fill in the blank: A material that does not allow electric current to flow through it easily is called an ____.
A material that does not allow electric current to flow through it easily is called an insulator. - 6
A flashlight uses batteries, wires, a switch, and a bulb. What does the switch do in the circuit?
A switch can make or break the path for current.
The switch opens or closes the circuit. When the switch closes the circuit, current can flow and the bulb can light. - 7
Look at a circuit with one battery, one bulb, and a closed switch. The wires connect all parts in one complete loop. Predict what happens to the bulb and explain why.
The bulb will light because the switch is closed and the circuit forms a complete path for electric current. - 8
A student wants to test whether aluminum foil conducts electricity. Describe a fair test using a battery, wires, and a bulb.
Put the material in the circuit where a wire would normally complete the loop.
The student can make a simple circuit with a battery, wires, and a bulb, leaving one gap. The student should place the aluminum foil in the gap and see if the bulb lights. If the bulb lights, the foil conducts electricity. - 9
Explain why electrical cords are often covered with plastic or rubber.
Electrical cords are covered with plastic or rubber because these materials are insulators. They help keep electric current inside the wire and help protect people from electric shock. - 10
A circuit has a battery, wires, and two bulbs connected one after the other in a single loop. If one bulb is removed, what happens to the other bulb? Explain.
In one single path, a break anywhere stops the current.
The other bulb will go out because removing one bulb creates a gap in the single loop. The open circuit stops current from flowing. - 11
Circle the materials that are usually good conductors: wood, silver, rubber, iron, glass, copper.
Silver, iron, and copper should be circled because they are metals, and metals are usually good conductors of electricity. - 12
A battery has a positive end and a negative end. Why must a simple circuit connect to both ends of the battery?
The battery pushes current around a complete loop.
A simple circuit must connect to both ends of the battery so electric current has a complete path from one end of the battery through the circuit and back to the other end. - 13
A student puts a wooden craft stick into a gap in a circuit. The bulb does not light. What can the student conclude about the wooden craft stick?
The student can conclude that the wooden craft stick is an insulator, or at least that it does not conduct enough electricity in this circuit to light the bulb. - 14
Draw and label a complete simple circuit using one battery, one bulb, one switch, and wires. Include labels for battery, bulb, switch, and wires.
Make sure there are no gaps in the loop if the bulb is on.
A correct drawing shows one battery, one bulb, one switch, and wires connected in a complete loop. The switch should be shown closed if the bulb is meant to light, and all four parts should be labeled. - 15
A toy stops working. The batteries are fresh, but one metal contact inside the battery holder is bent away from the battery. Explain why the toy does not work.
Even a small gap can open a circuit.
The toy does not work because the bent metal contact creates a gap in the circuit. Without a complete path touching the battery, electric current cannot flow through the toy.