1.The resistance material used for meter shunts is chosen for its very low value of

temperature coefficient of resistance. Why is this so? 2.State briefly with the aid of circuit diagrams

(a) how to extend the range of a 0–110 V AC voltmeter to read (i) 220 V and

(ii) 22 kV;

(b) how to extend the range of a 0–5 A AC ammeter to read 500 V;

(c) how to extend the range of a 0.5 A DC ammeter to read 500 A.

3.Draw a circuit diagram showing a single-phase wattmeter measuring the power in a single-phase 6.6 kV 500Acircuit by means of current and voltage transformers.

4.Calculate the sensitivity in ohms/volt of voltmeters giving full-scale deflection with currents of (a) 10 mA, (b) 0.5 mA and (c) 50 μA.