Discussion Forum



1)

Resistances 1Ω, 2Ω and 3Ω are connected to form a triangle. If a 1.5 V cell of negligible internal resistance is connected across the 3 Ω resistor, the current flowing through this resistor will be


A) 0.25A

B) 0.5A

C) 1.0A

D) 1.5 A

Answer:

Option B

Explanation:

Equivalent resistance between A and B = series combination of 1Ω and 2Ω in paralell with 3Ω resistor

2152021710_180096_205193_ans.png

$\frac{1}{R}=\frac{1}{3}+\frac{1}{3}=\frac{2}{3}$ or R = 1.5 Ω

.'. Current in the circuit is I = V/R = 1.5/1.5 = 1A

Since the resistance in arm ACB = resistance in arm AB = 3 Ω, the current divides equally in the two arms. Hence the current through the 3 Ω resistor = I/2 = 0.5 A.