8 Fig. 8.1 shows an electrical circuit. one metre resistance wire 12.0V d.c. C sliding contact (ii) Explain your answer to (i). R Fig. 8.1 The resistance of the lamp is 4.09 when it is at its normal brightness. (a) The lamp is rated at 6.0V, 9.0W. Calculate the current in the lamp when it is at its normal brightness. (ii) the potential difference across the 4.092 resistor R. 4.092 (b) The sliding contact C is moved to A. The lamp lights at its normal brightness. Calculate (i) the total circuit resistance, current= resistance = potential difference = (c) The sliding contact C is moved from A to B. (i) Describe any change that occurs in the brightness of the lamp. N .[2] ..[1] ..[1] ...[1] .[2]​