Question

Assertion (A): All stereo broadcasting uses quadrature carrier multiplexing (QAM). Reason (R): QAM involves more stringent synchronization than FM system with 558 subcarrier modulation.

• A. Both (A) and (R) are correct and (R) is correct explanation
• B. Both (A) and (R) are correct but (R) is not explanation
• C. (A) is correct but (R) is incorrect
• D. (A) is incorrect but (R) is correct

Hint:

FM stereo uses multiplexing, not QAM.

Answer 1

The Correct Option is D

Concept: Stereo FM uses multiplexing, not pure QAM.

Step 1: Assertion Stereo FM uses multiplexing with subcarriers, not QAM. \[ \Rightarrow \text{Assertion is FALSE} \]

Step 2: Reason QAM requires phase synchronization → more stringent. \[ \Rightarrow \text{Reason is TRUE} \] \[ \therefore \text{Correct answer is (D)} \]