The internal resistance of a 2.1 V cell which gives a current of 0.2 A through a resistance of 10Ω is

Question

The internal resistance of a 2.1 V cell which gives a current of 0.2 A through a resistance of 10Ω is (A) 1.0 Ω  (B) 0.2 Ω  (C) 0.5 Ω  (D) 0.8 Ω

Tardigrade Admin · Accepted Answer

I =( E / R + r ) 0.2 ×(10+ r )=2.1 10+ r =(2.1/2) × 10 r =10.5-10=0.5 Ω

Q. The internal resistance of a $2.1 V$ cell which gives a current of $0.2 A$ through a resistance of $10Ω$ is