Match List – I with List – II.
| LIST I | LIST II | ||
|---|---|---|---|
| A. | Transducer | I. | High frequency wave |
| B. | Modulated Waves | II. | Receiver |
| C. | Band width | III. | Provides output in electrical form |
| D. | Demodulator | IV. | Range of frequencies over which communication system works. |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → A-III, B-I, C-IV, D-II
These are the basic terms of a communication system: a signal is converted, modulated on a carrier, sent through the channel and recovered at the receiver.
(A) Transducer — this matches (III) Provides output in electrical form. A transducer converts a quantity such as sound or pressure into an electrical signal (and the reverse), so its output or input is electrical.
(B) Modulated Waves — this matches (I) High frequency wave. In modulation the low-frequency message signal is carried by a high-frequency carrier wave, and the result is the modulated wave.
(C) Band width — this matches (IV) Range of frequencies over which communication system works. It is the range of frequencies a signal or a system occupies.
(D) Demodulator — this matches (II) Receiver. Demodulation (detection) recovers the message from the modulated wave, and it is done in the receiver.
Note: This question is from the pre-rationalised NCERT book (2022-23). The topic was removed from the latest NCERT book (2026-27), and it also appears to be out of the CUET 2026 syllabus.
NCERT (Pre-rationalised edition, 2022-23):
Basic Terminology Used in Electronic Communication Systems – “… (i) Transducer: … In electronic communication systems, we usually come across devices that have either their inputs or outputs in the electrical form. … (ix) Bandwidth: Bandwidth refers to the frequency range over which an equipment operates or the portion of the spectrum occupied by the signal. (x) Modulation: … Therefore, at the transmitter, information contained in the low frequency message signal is superimposed on a high frequency wave, which acts as a carrier of the information. This process is known as modulation. (xi) Demodulation: The process of retrieval of information from the carrier wave at the receiver is termed demodulation.”