A photo cell is receiving light from a source placed at a distance of `1 m`. If the same source is to be placed at a distance of `2 m` , then the ejected electron

Options

A. Moves with one - fourth energy as that of the initial energy
B. Moves with one - fourth of momentum as that of the initial momentum
C. will be half in number
D. will be one - fourth in number

Answer

D

Explanation

Number of ejected electrons
`prop (Intensity) prop (1)/((Distance)^(2))`
Therefore an increament of distance two times will reduce the number of ejected electrons to `(1)/(4) th` of the previous one.