Question

The following table presents the part of the electromagnetic spectrum and their corresponding major applications. Match the following and choose the correct option. \[ \begin{array}{|c|c|c|c|} \hline \text{Part of Spectrum} & & \text{Applications} & \\ \hline P & \text{Microwave} & I & \text{For purifying water} \\ \hline Q & \text{UV rays} & II & \text{For warming food} \\ \hline R & \text{Gamma rays} & III & \text{For AM and FM communication systems} \\ \hline S & \text{Radio waves} & IV & \text{Cancer cells treatment} \\ \hline \end{array} \]

• A. P-II, Q-IV, R-III, S-I
• B. P-I, Q-II, R-III, S-IV
• C. P-I, Q-IV, R-II, S-III
• D. P-II, Q-I, R-IV, S-III

Hint:

Microwaves → Cooking UV rays → Water purification Gamma rays → Cancer treatment Radio waves → Communication These are among the most frequently asked electromagnetic spectrum applications in competitive examinations.

Answer 1

The Correct Option is D

Step 1: Understand the task.
We match each region of the electromagnetic spectrum (microwave, UV, gamma, radio) to its common application.
Step 2: Microwaves.
Water molecules absorb microwaves strongly and heat up, which is how microwave ovens warm food. So $P \to II$ (warming food).
Step 3: Ultraviolet rays.
UV photons carry enough energy to kill microorganisms, so UV is used to purify water. So $Q \to I$ (purifying water).
Step 4: Gamma rays.
Gamma rays have very high energy and penetrate deeply, so they are used in radiotherapy to destroy cancer cells. So $R \to IV$ (cancer cell treatment).
Step 5: Radio waves.
Radio waves carry AM and FM broadcast signals, so $S \to III$ (AM and FM communication).
Step 6: Assemble the match.
The complete matching is $P$-$II$, $Q$-$I$, $R$-$IV$, $S$-$III$, which is option (D).
\[ \boxed{\text{P-II, Q-I, R-IV, S-III}} \]