Case: Read the passage and answer the question.
The electromagnetic (EM) spectrum is the range of all types of EM radiation. Radiation is energy that travels and spreads out as it goes – the visible light that comes from a lamp in your house and the radio waves that come from a radio station are two types of electromagnetic radiation. The other types of EM radiation that make up the electromagnetic spectrum are microwaves, infrared light, ultraviolet rays, X-rays and gamma rays.
Match List-I (radiation) with List-II (its effect on matter).
| List-I | List-II |
|---|---|
| (A) Infrared waves | (I) Can damage or destroy living tissues |
| (B) Visible light | (II) Makes whole atoms and molecules vibrate and raises the temperature |
| (C) Ultraviolet rays | (III) Causes more melanin to form in the skin |
| (D) X-rays | (IV) Is detected by the human eye |
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)-(III), (D)-(I)
Electromagnetic waves act on matter through their electric and magnetic fields. The way a wave acts depends on its wavelength or frequency.
(A) Infrared waves — This matches (II). Infrared waves have lower frequencies than visible light. They set whole atoms and molecules vibrating, so the internal energy and the temperature rise.
(B) Visible light — This matches (IV). Our eyes are sensitive to wavelengths of about 700 nm to 400 nm.
(C) Ultraviolet rays — This matches (III). Exposure to UV makes the skin produce more melanin, and the skin gets tanned.
(D) X-rays — This matches (I). X-rays can damage or destroy living tissues, so unnecessary exposure to them is avoided.
NCERT (2026-27):
Points to Ponder – “3. Infrared waves, with frequencies lower than those of visible light, vibrate not only the electrons, but entire atoms or molecules of a substance. This vibration increases the internal energy and consequently, the temperature of the substance. …”
Visible rays – “It is the part of the spectrum that is detected by the human eye.”
Ultraviolet rays – “Exposure to UV radiation induces the production of more melanin, causing tanning of the skin.”
X-rays – “Because X-rays damage or destroy living tissues and organisms, care must be taken to avoid unnecessary or over exposure.”