The expected answers were:

(a) R / /branch = __30____x2____0__Ω = __30x20__Ω = 120

30+20 50

Effective resistance= 10 + 20 + 120 = __42Ω __

(b) Current thro' 30Ω resistor 20 / 50 *x **2.5**A *= *50 / 50 A *= *lA *

Voltage across 30Ω resistor = 30 xlV = __30 ____V __

V_{R30} = R//Branch x I_{T}

= 12 x 2.5

= 30V

(c)Voltage applied to circuit, V = 2.5 x 42 V = __105 ____V __

{d} P_{R10} = I² RlO

= 2.5 x 2.5 x 10

= 62.5 W

For Questions 2, three important theorems of circuit theory were
required namely: equivalent resistance for resistors connected in parallel
and in series, Ohm's law and the current divider rule.

The question was on Basic Electrical Theory. The question was popular
with the candidates. Many candidates that attempted as may be
expected scored full marks.