The graph of Fig. shows the variation of photoelectric current (I) versus applied voltage (V) for the two different photosensitive materials for two different intensities of the incident radiation. Identify the pairs of curves that correspond to different materials but same intensity of incident radiation.

Options

A. Curve `1` and `3`,Curve `2` and `4`
B. Curve `1` and `2`,Curve `3` and `4`
C. Curve `1` and `4`,Curve `2` and `3`
D. Curve `1` only,Curve `2` and `4`

Answer

A

Explanation

Curves 1 and 3 (different materials due to different stopping potentials )
(b) Curves 2 and 4 (same intensity due to same current)