What is the effective annual rate of interest corresponding to a nominal rate of 10% per annum payable half-yearly?

10.25%

Amount = P$(1 + \frac{R}{100})^t$

Amount of Rs 100 for 1 year when compounded half-yearly,

⇒ Amount =  100$(1 + \frac{5}{100})^2$

                = 100 x $\frac{441}{400}$

                = 110.25

Effective rate = (110.25 - 100)%

                    = 10.25%