A moving-coil instrument, which gives full-scale deflection with 0.015 A has a copper coil having resistance of 1.5 Ohm at 15°C and a temperature coefficient of 1/234.5 at 0 degree C in series with a swamp resistance 3.5 Ohm having a negligible temperature coefficient. Determine the resistance of shunt required for a full-scale deflection of 20 A and the resistant required for a full-scale deflection of 250 V. If the instrument reads correctly at 15°C, determine the percentage error in each case when the temperature is 25°C.
