Match List - I with List - II.
| List – I (Message Signal) | List – II (Band width) | ||
|---|---|---|---|
| (A) | Speech | (I) | 20 kHz |
| (B) | TV Signal | (II) | 2800 Hz |
| (C) | Video for pictures | (III) | 6 MHz |
| (D) | Music | (IV) | 4.2 MHz |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → (A)-(II), (B)-(III), (C)-(IV), (D)-(I)
(A) Speech — this matches (II) 2800 Hz. Speech needs the range 300 Hz to 3100 Hz, a bandwidth of 2800 Hz.
(B) TV Signal — this matches (III) 6 MHz. A TV signal carries both voice and picture and is allotted 6 MHz.
(C) Video for pictures — this matches (IV) 4.2 MHz. Picture (video) signals alone need about 4.2 MHz.
(D) Music — this matches (I) 20 kHz. Music has high frequencies and needs about 20 kHz.
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):
Bandwidth of Signals – “… For speech signals, frequency range 300 Hz to 3100 Hz is considered adequate. Therefore speech signal requires a bandwidth of 2800 Hz (3100 Hz – 300 Hz) for commercial telephonic communication. To transmit music, an approximate bandwidth of 20 kHz is required because of the high frequencies produced by the musical instruments. … Video signals for transmission of pictures require about 4.2 MHz of bandwidth. A TV signal contains both voice and picture and is usually allocated 6 MHz of bandwidth for transmission.”