Consider a simple circuit shown in figure stands for a variable resistance R. R can very from `R_(0)` to infinity. `r` is internal resistance of the battery
(r `lt lt R lt lt R_(0)`) .

(a) Potential drop across AB is nearly constant as R' is varied.
(b) Current through R' is nearly a constant as R' is varied.
(c) Current I depends sensitively on R'.
(d) `I ge (V)/(r + R)` always.

Options

A. Potential drop across AB is nearly constant as R' is varied.
B. Current through R' is nearly a constant as R' is varied.
C. Current I depends sensitively on R'.
D. `I ge (V)/(r + R)` always.

Explanation

(A,D)
In parallel connection of resistors equivalent resistance is smaller than smallest value of resistance.
Potential difference is obtained across AB and r. Equivalent resistance of R and R. is always smaller than R. Hence , I `ge (V)/(r + R)` and as equivalent of parallel connection of R. and R is less than R and nearly equal to R. Hence, variation in R. won.t change p.d. across AB .