# NEET Questions Solved

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

(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

(d) Number of ejected electrons ∝ (Intensity) ∝ $\frac{1}{{\left(\mathrm{Distance}\right)}^{2}}$
Therefore an increment of distance two times will reduce the number of ejected electrons to $\frac{1}{4}\mathrm{th}$ of the previous one.

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