In a historical experiment to determine Planck's constant, a metal surface was irradiated with light of different wavelengths. The emitted photoelectron energies were measured by applying a stopping potential. The relevant data for the wavelength $\left(\lambda \right)$ of incident light and the corresponding stopping potential $\left(V_0\right)$ are given below:
 

$\lambda \left(\mu m\right)$	$V_0\left(Volt\right)$
0.3	2.0
0.4	1.0
0.5	0.4

Given that $c=3\times {10}^8 m{s}^{-1} and e=1.6\times {10}^{-19}C,$ Planck's constant (in units of J s) found from such an experiment is :

• A

  $6.0\times {10}^{-34}$
• Correct answer
  B

  $6.4\times {10}^{-34}$
• C

  $6.6\times {10}^{-34}$
• D

  $6.8\times {10}^{-34}$

Hence, the correct answer is option: 'B'.