Question

A current of 0.3 A is flowing through a branch of 6 Ω resistors in a junction as shown in fig. . Calculate the
(a) P.d. across the junction XY,
(b) Current flowing through 9Ω and 24Ω
( c) P.d. across 24 Ω resistor, and
( d) e.m.f. of the cell.

Answer 1

(a) Potential difference across XY = pot. cliff. across 6 Ω resistor
= 0.3 x 6=1.8V

b) Pot. difference across 9Ω resistor= pot. cliff. across 6 Ω resistor= 1.8 V
:. Current through 9Ω resistor = `1.8/9` = 0.2A

Current through 2.4Ω resistor = total current in the circuit = 0.3 + 0.2 = 0.5A
(c) p.d. across 2.4Ω resistor = 0.5 x 2.4 = 1.2 V
(d) emf of cell = p.d across 2.4Ω resistor+ pot cliff. across XY = 1.2 + 1.8 = 3.0 V