Question

Match List-I (modulation/generation techniques) with List-II (disadvantages/generated signal) and select the correct answer from the given codes:

• A. A - II, B - IV, C - I, D - III
• B. A - III, B - I, C - IV, D - II
• C. A - IV, B - I, C - II, D - III
• D. A - III, B - IV, C - I, D - II

Hint:

Associate key terms with modulation schemes: - PCM \(\leftrightarrow\) Quantization Noise - Delta Modulation \(\leftrightarrow\) Granular Noise \& Slope Overload - FM \(\leftrightarrow\) Threshold Effect - Ring Modulator \(\leftrightarrow\) DSB-SC

Answer 1

The Correct Option is D

Step 1: Analyze each item in List-I.

(A) Ring Modulator: This circuit generates a (III) DSB-SC (Double-Sideband Suppressed-Carrier) signal by multiplying the carrier and message signal.
(B) Pulse Code Modulation (PCM): This digital representation of an analog signal involves sampling and quantization. The error from representing continuous amplitudes with discrete levels is (IV) Quantization noise.
(C) Delta Modulation (DM): This digital modulation transmits a 1-bit code indicating signal increase or decrease. DM's key issues are slope overload distortion and (I) Granular noise, which occurs when the signal is relatively flat.
(D) Frequency Modulation (FM): A disadvantage of FM detection with simple detectors is the (II) Threshold effect. Below a specific carrier-to-noise ratio, the output signal-to-noise ratio significantly degrades.

Step 2: Combine the matches.The correct matching is: A-III, B-IV, C-I, D-II.