Question

Two sources of emf 6V and internal resistance 3W and 2W are connected to an external resistance R as shown. If potential difference across battery A is zero, then value of R is-

• A. 1W
• B. 2W
• C. 3W
• D. 4W

Answer 1

Answer: (A)

1W

Answer 2

i =

potential difference across A = 0

6 – $\frac { 12 \times 3 } { \mathrm { R } + 5 }$ = 0

R = 1 W