An upolarised beam of intensity `2a^(2)` passes through a thin polarioid. Assuming zero absorption in the polariod, the intensity of emergent plane polarised light is

Options

A. `2a^(2)`
B. `a^(2)`
C. `sqrt(2)a^(2)`
D. `a^(2)/2`

Answer

B

Explanation

the intensity of plane polarised light = `2a^(2)`.
`therefore` Intensity of polarised light from first nicol prism
`I_(0)/2 = 1/2 xx 2a^(2) = a^(2)`