2. Electricity

Question 1

1. Draw the symbol for a cell.

Answer 1

Question 2

2. How must an ammeter be placed in a circuit? What is it used to measure?

Answer 2

2. In series, used to measure current

Question 3

3. How must a voltmeter be placed in a circuit? What is it used to measure?

Answer 3

In parallel, used to measure potential difference

Question 4

4. Draw the symbol for a lamp.

Answer 4

4

Question 5

5. Draw the symbol for a resistor.

Answer 5

5

Question 6

6. What is difference between series and parallel circuits?

Answer 6

6. Series – all components in one loop. Parallel – components in separate loops.

Question 7

7. What are the units for charge?

Answer 7

7. Coulombs (C)

Question 8

8. What is current? What are the units for current?

Answer 8

8. Rate of flow of charge, Amps (A)

Question 9

9. What is potential difference? What are the units of potential difference?

Answer 9

9. Energy transferred per coulomb of charge, Volts (V)

Question 10

10.What is resistance? What are the units for resistance?

Answer 10

10. The opposition to the flow of current, Ohms (Ω)

Question 11

11.Why does increasing temperature increase resistance?

Answer 11

11. Atoms in the wire vibrate more which slows the current down

Question 12

12.How does current behave in a series circuit?

Answer 12

12. It is the same all round the circuit

Question 13

13.How does potential difference behave in a series circuit?

Answer 13

13. Potential difference is shared between the components in the circuit

Question 14

14.How does resistance behave in a series circuit?

Answer 14

14. Total resistance = add up all the resistances in the circuit

Question 15

15.How does current behave in a parallel circuit?

Answer 15

15. Current is shared between the loops of the circuit

Question 16

16.How does potential difference behave in a parallel circuit?

Answer 16

16. Potential difference is the same

Question 17

17.How does resistance behave in a parallel circuit?

Answer 17

17. The more loops there are the lower the resistance

Question 18

18.Draw the current-potential different graph for an ohmic resistor.

Answer 18

18.

Question 19

19.Describe the relationship between current and potential difference through a resistor (at a constant temperature)

Answer 19

19. As current increases potential difference increases.

Question 20

20.What is the voltage and frequency of mains electricity in the UK?

Answer 20

20. 230V, 50Hz

Question 21

21.What is the difference between direct current and alternating current (A.C.)?

Answer 21

21. DC goes in one direction, AC rapidly changes direction

Question 22

22.What is the role of a fuse in the plug?

Answer 22

22. The fuse is a thin piece of wire which will melt if the current is too high

Question 23

23.What is the National Grid?

Answer 23

23. A series of cables and transformers to get electricity around the country (from power stations to homes and businesses)

Question 24

24.What do step up and step down transformers do?

Answer 24

24. Step up the voltage to reduce energy loss when electricity goes through the cables. Step down the voltage to make it safe in our homes