The compound interest paid when a sum of ₹20,000 is invested for 1 year 4 months at 7\( \frac{1}{2} \)% compound interest per annum, compounded annually, is:
A wire of length L and resistance R is reformed so that its length increases by 25% with no change in its volume. The resistance of the new wire is:
\( \frac{4}{5} \) R
\( \frac{25}{16} \) R
\( \frac{5}{4} \) R
\( \frac{16}{25} \) R