Question 2
Figure 1 is a d.c. circuit.
Calculate the:
(i) total resistance of the circuit;
(ii) current (I) in the circuit;
(iii) power dissipated in the circuit.
The expected responses were:
- First, each of the two resistors connected in series are reduced to one according to
R ser-eq= R1 + R2 = 1 + 1(= 2Ω); 2 + 2 (= 4Ω); 2 + 2 (= 4Ω).
The resulting equivalent parallel combination will give a total resistance of
(ii) Current (I) in the circuit is given by:
(iii)Power dissipated in the circuit is evaluated as
The Chief Examiner reported that majority of the candidates that attempted this question responded very well. The report indicated that, a very large percentage of them were able to correctly determine the total resistance and apply the appropriate formulas for the calculation of current and power dissipated respectively..