Radiation of wavelength $\lambda$ , is incident on a photocell. The fastest emitted electron has speed v. If the wavelength is changed to $\large\frac{3 \lambda}{4}$, the speed of the fastest emitted electron will be :

Question

$\begin{array}{1 1} (1) > v \bigg(\frac{4}{3}\bigg)^{1/2} \\(2) < v \bigg(\frac{4}{3}\bigg)^{1/2} \\ (3) = v \bigg(\frac{4}{3}\bigg)^{1/2} \\ (4) = v \bigg(\frac{3}{4}\bigg)^{1/2} \end{array}$