Identify the correct statements.
(A) Photographic plates are sensitive to infrared waves.
(B) Infra-red waves are invisible but can cast shadows like visible light.
(C) Photographic plates are sensitive to ultraviolet rays.
(D) Infrared photons have more energy than photons of visible light.
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → (A), (B) and (C) only
(A) Photographic plates are sensitive to infrared waves. — Correct. Special photographic plates are sensitive to infrared radiation and are used for infrared photography.
(B) Infra-red waves are invisible but can cast shadows like visible light. — Correct. Infrared waves travel in straight lines like visible light, so an opaque object blocks them and casts a shadow.
(C) Photographic plates are sensitive to ultraviolet rays. — Correct. Ultraviolet rays affect photographic plates, as visible light does.
(D) Infrared photons have more energy than photons of visible light. — Incorrect. The photon energy is \( E = hc/\lambda \), and infrared has a longer wavelength than visible light, so an infrared photon has less energy.
So the correct statements are (A), (B) and (C), which is Option (1).