The value of Plank's constant, if the slope of the graph of stopping potential vs frequency of incident light is $4\times {10}^{-15} \mathrm{V} \mathrm{s}$ is (given charge of an electron $=1.6\times {10}^{-19} \mathrm{C}$)

• A

  $6.0\times {10}^{-34} \mathrm{J} \mathrm{s}$
• B

  $6.2\times {10}^{-34} \mathrm{J} \mathrm{s}$
• Correct answer
  C

  $6.4\times {10}^{-34} \mathrm{J} \mathrm{s}$
• D

  $6.6\times {10}^{-34} \mathrm{J} \mathrm{s}$

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