Match electromagnetic-spectrum regions with their principal applications. P: microwaves; Q: UV rays; R: gamma rays; S: radio waves. Applications I: water purification; II: food warming; III: AM/FM communication; IV: cancer-cell treatment.
Options

Question

Match electromagnetic-spectrum regions with their principal applications. P: microwaves; Q: UV rays; R: gamma rays; S: radio waves. Applications I: water purification; II: food warming; III: AM/FM communication; IV: cancer-cell treatment.

Options

G1 Physics · Accepted Answer

Step 1: Microwaves can heat water-containing food by dielectric heating, so P → II. Step 2: UV radiation is germicidal and is used for water purification, so Q → I. Step 3: High-energy gamma radiation can be used to destroy malignant cells in radiotherapy, so R → IV. Step 4: Radio waves carry broadcast AM and FM signals, so S → III. Step 5: Combined mapping is P–II, Q–I, R–IV, S–III. Final answer: Option C.