When a resistor of resistance R is connected across a.c. the terminal p.d. of the cell is reduced to three-quart its e.m.f. The cell’s internal resistance in terms of R is
\(\frac{R}{4}\)
\(\frac{R}{3}\)
\(\frac{R}{2}\)
2\(\frac{R}{3}\)
R
Correct answer is A
No explanation has been provided for this answer.