ELECTRICITY

A bulb in a circuit can be made brighter by adding more batteries.

A bulb in a circuit can be made dimmer by using less batteries.

Some objects can conduct electricity while the others cannot.

A switch is used to complete or break a circuit.


QUIZZES


1. A material that lets electricity pass through it is called ...
an electrical conductor
an electrical insulator
an electrical appliance


2. A material that does not let electricity pass through it is called ...
an electrical conductor
an electrical insulator
an electrical appliance


3. Which of the following materials is an electrical conductor?
Silver
Silver-coloured plastic
Cork


4. Which of the following materials is an electrical insulator?
Aluminium
Gold
Rubber


5. In which circuit will the bulb or bulbs glow brightest?
A simple circuit with one bulb and one battery
A simple circuit with one bulb and two batteries
A simple circuit with two bulbs and one battery


6. Why is a bulb brighter when it is powered by two batteries rather than one?
Because the flow of electricity in the circuit is less
Because the flow of electricity in the circuit is the same
Because the flow of electricity in the circuit is greater


7. Ruby has connected two bulbs across two batteries in a simple circuit. How can she make the bulbs dimmer?
Replace one of the batteries with a section of wire
Replace one of the batteries with a cork
Replace one of the bulbs with a section of wire


8. Ruby makes a complete simple circuit with one bulb and three batteries. The bulb lights for an instant and then goes out. Why?
Not enough electricity flows around the circuit
Too much electricity flows through the bulb's filament
The batteries are flat


9. Why is electrical wiring usually made from copper?
Because copper is shiny
Because copper conducts electricity
Because copper is not magnetic


10. Why is electrical wiring usually covered with a layer of plastic?
To make it look pretty
To help electricity flow along the wire
To make it safe

11. In a simple series circuit, why does the bulb light when you close the switch?
Because the switch produces electricity
Because closing the switch completes the circuit
Because closing the switch breaks the circuit


12. In a simple series circuit, why does the bulb go out when you open the switch?
Because the battery goes flat
Because opening the switch breaks the circuit
Because too much electricity flows through the bulb


13. Imagine a simple series circuit with one 1.5V battery and one bulb. When the 1.5V battery is replaced with a 3V battery ...
the bulb gets brighter
the bulb gets dimmer
the bulb stays at the same level of brightness


14. Imagine a circuit with a 1.5V battery and one bulb. Imagine a similar circuit with a 3V battery and two bulbs. Which has the brightest bulbs?
The circuit with a 1.5V battery and one bulb
The circuit with a 3V battery and two bulbs
The bulbs in both circuits are of similar brightness levels


15. Why might a bulb flash and go out when a 1.5V battery and a 3V battery are both connected across it in a simple series circuit?
There is not enough electricity flowing around the circuit
Too much electricity flows through the bulb's filament and the bulb blows
The batteries are flat


16. What is the effect of changing the wire in a circuit from a straight thick wire to a straight thin wire?
The bulbs become dimmer
The bulbs become brighter
The bulbs stay at the same level of brightness


17. What is the effect of changing the wire in a circuit from a straight thick wire to a longer (coiled) thick wire?
The bulbs become dimmer
The bulbs become brighter
The bulbs stay at the same level of brightness


18. In a circuit diagram, what does a circle with a cross inside it represent?
A light bulb
A motor
A battery


19. What do the long straight lines represent in a circuit diagram?
Motors
Light bulbs
Wires


20. How is a battery represented in a circuit diagram?
By a circle with a cross inside it
By a circle with an M inside it
By a long line and a short line

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