7j Electricity Test Sen 2004

You may write on this sheet

Name: __________________________

Tutor group: ____________

For questions 1 to 9 chose the correct word from each set of brackets to make each sentence correct and underline it. 1. To make an electric device work you need a (plastic/cell/complete/incomplete) circuit. 2. Wires have metal in them because they (generate/resist/produce/conduct) electricity 3. An electric bulb gives out (light/sound/chemical/nuclear) energy and heat energy. 4. The flow of electricity through a wire is called (current/electron/voltage/power). 5. A small wire that melts if the current gets too big is called a (filament/fuse/fail). 6. Electric current is measured in (Amps/volts/ohms/seconds) 7. Electric current is measured in (Amps/volts/ohms/seconds) 8. A longer wire will be more difficult for electrons to flow through. We say that the longer wire has a bigger (resistor/resistance/resist/refraction) 9. The more bulbs that you put in series in a circuit, the (brighter/dimmer/hotter) they become. This is because there is more (resistor/resistance/resist/refraction) in the circuit.

Look at diagrams A to D to answer questions 9 to 13. 10.

In which of the circuits above are the bulbs brightest? A, B, C or D? ____

11.

What type of circuit is A?

____________________

12.

What type of circuit is C?

______________________________

13. What is wrong with circuit B if it is meant to light up the two bulbs? ________________________________________________________ ____________________________________

Look at the circuit opposite. Decide which A

of the switches A to E correctly answer questions 14 to 17

B

14.

Which switch controls all the bulbs? ____

15.

Which switch controls only bulb 1?

____

16.

Which switch controls only bulb 3?

____

17.

Which switch controls bulbs 2 and 3 but

not bulb 1?

_____

E

C

D

Look at the diagram below before answering questions 18 to 19. 18.

If the wire was replaced with

50 cm of the same wire, what would happen to the brightness of the bulb? ___________________________ 19.

If the original wire was replaced

with thicker wire of the same material and

100cm of thin copper wire

same length, what would happen to the brightness of the bulb? ____________________________ 20.

Draw a circuit to show: two cells, a switch and two lamps all connected in

series.

21.

If one lamp 'blows' in the circuit you have drawn what will happen to the

other lamp? ______________________________________________ 22.

Explain your answer to question 21 _________________________

__________________________________________________________ 23.

If you connect another lamp in the series circuit, what happens to the

brightness of all the lamps?

______________________________________

24.

Explain your answer to question 23

___________________________

___________________________________________________________ __________________________________________________________ 25.

Draw a circuit to show: two cells, a switch and two lamps. Show the lamps

connected in parallel.

26.

If one lamp 'blows' what will happen to the other lamp in the parallel circuit?

______________________________________________________________ 27.

Explain your answer to question 26

____________________________

__________________________________________________________ __________________________________________________________ Explaining electricity can be helped by imagining water flowing around pipes. For questions 28 to 30 match up which of the electrical devices in the left hand list is like which object on the right hand list. (Write the letter) 28. The thin filament wire inside a bulb ______ 29. The battery ___

30. A switch _____

A: A clamp that squeezes the hose pipe

B: A part of a hose pipe that is much thinner than the rest of the hose pipe. C: A water pump that makes the water flow through a hose.

Now go back and check your work to make sure you haven’t made any silly mistakes.