In a photoelectric experiment, it was found that the stopping potential decreases from 1.85 V to 0.82 V as the wavelength of the incident light is varied from 300nm to 400nm. Calculate the value of the Planck constant from these data.

Explanation

To calculate the value of Planck's constant from the given data in the photoelectric experiment, we will follow these steps:

### Step 1: Understand the relationship between stopping potential, wavelength, and Planck's constant
The maximum kinetic energy (K.E.) of the photoelectrons can be expressed as:
\[ K.E. = \frac{hc}{\lambda} - \phi \]
Where:
- \( K.E. \) is the maximum kinetic energy of the photoelectrons,
- \( h \) is Planck's constant,
...