In the experimental arrangement for the study of the photoelectric effect, C is the emitter plate and A is the collector plate. Match List-I with List-II.
| List-I | List-II |
|---|---|
| (A) Quartz window sealed on the glass tube | (I) Varies the frequency of the light falling on plate C |
| (B) Commutator | (II) Lets ultraviolet radiation reach plate C |
| (C) Coloured filter in the path of the light | (III) Varies the intensity of the light falling on plate C |
| (D) Changing the distance of the light source from plate C | (IV) Reverses the polarity of plates C and A |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → (A)-(II), (B)-(IV), (C)-(I), (D)-(III)
(A) Quartz window sealed on the glass tube — This matches (II). Quartz is transparent to ultraviolet radiation, so the radiation passes through the window and falls on plate C.
(B) Commutator — This matches (IV). It reverses the connections of the plates. So plate A can be made positive or negative with respect to plate C.
(C) Coloured filter in the path of the light — This matches (I). A filter lets through light of one colour only, so the frequency of the light on plate C changes.
(D) Changing the distance of the light source from plate C — This matches (III). Moving the source away makes the light on plate C weaker. Moving it closer makes the light stronger.
NCERT (2026-27):
Experimental Study of Photoelectric Effect – “… A transparent quartz window is sealed on to the glass tube, which permits ultraviolet radiation to pass through it and irradiate the photosensitive plate C. …”
Experimental Study of Photoelectric Effect – “… The polarity of the plates C and A can be reversed by a commutator. …”
Experimental Study of Photoelectric Effect – “… Light of different frequencies can be used by putting appropriate coloured filter or coloured glass in the path of light falling on the emitter C. The intensity of light is varied by changing the distance of the light source from the emitter.”