A parallel beam of light is incident on a converging lens parallel to its principal axis. As one moves away

Monjur Alahi

A parallel beam of light is incident on a converging lens parallel to its principal axis. As one moves away from the lens on the other side on its principal axis, the intensity of light

(a) remains, constant

(b) continuously increases

(c) continuously decreases

(d) first increases then decreases.


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Salim Ahmed Kawsar

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(d) first increases then decreases.

EXPLANATION: 

The parallel beam of light converges at the focus on the other side and then diverges. Hence till the person moves to the focus the intensity will increase. Beyond the focus, it will decrease. Hence the option (d).

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