Question

A 5V battery with internal resistance 2Ω and 2V battery with  internal resistance 1Ω are connected to 10Ω resistor as shown in fig the current in 10Ω resistor is....

(A) 0.27A, P₁ to P₂ 

(B) 0.27A, P₂ to P₁

(C) 0.03A, P₁ to P₂

(D) 0.03A, P₂ to P₁

Answer 1

The correct option (D) 0.03A, P₂ to P₁

Explanation:

Let potential at P₂ be V. & current flows from P₂ to P₁.

∴ by applying current law at P₂, I₁ + I₂ + I₃ = 0

∴ {(V – 5)/2} + (V/10) + {(V + 2)/1} = 0

∴ {(5V + 25 + V + 10V + 20)/10} = 0

∴ 16V = 5

V = 5/16

∴ current through 10Ω resistor = I₂ = (V/10) = (5/16) × (1/10)

= (1/32) A

I₂ = 0.03A, from P₂ to P₁