Chapter 2 Electricity Date:__________________

Exercises:1. Diagram 4.1 shows a circuit used to investigate the

relationship between current and potential difference across a constantan wire s.w.g 24 with length of 10 cm.

(a)Name the measuring instruments labelled X and Y in

Diagram 4.1.

X = .................................. Y = ..................................(b) (i) What is the relationship between the reading of

the measuring instruments X and Y?

................................................................................(ii) State the physics law involved in 4(b)(i).

................................................................................(c) The experiment is repeated by using a constantan

wire s.w.g 36 with the same length. Diagram 4.2 shows the graph V against T for the experiment.

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Based on graph in Diagram 4.2;(i) What is the physical quantity represented by the gradient

of the graph?

................................................................................ (ii) Which of the constantan wire has the highest resistance?

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2. Diagram 2.1 shows two constantan wires P and Q of the same length but of different cross-sectional area, being used to carry out an experiment.

Initialy, the experiment

is carried out with P placed across XY. After that, P is replaced with Q and

the experiment is repeated. The V-I graph in Diagram 2.2 shows the results obtained from the experiment.

a)a)a)a)a)

Based on Diagram 2.1, compare the cross sectional area of wires P and Q.

................................................................................b) Based on Diagram 2.2:

(i) State how the resistance of the constantan wire can be obtained.

................................................................................ (ii) Determine the resistance of conductor Q. Show on

your graph.

3. The electrical components in our household appliances are connected in a combination of series and parallel circuits. (pg58)

The above figure shows a hair dryer which has components connected in series and parallel. Describe how the circuit works.

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