In one experiment 1900 photons are detected in a 0210mm wide

In one experiment, 1900 photons are detected in a 0.210mm wide strip where the amplitude of the electromagnetic wave is 12.0V/m. How many photons are detected in a nearby 0.210mm wide strip where the amplitude is 30.0V/m? (Do not enter a unit with your answer.)

Solution

Since

N₂/N₁ =(E₂/E₁)

N₂/1900 = (30/12)

N₂ = 4750