Which of the following statement(s) is/are true regarding Data Communication?…
2021
Which of the following statement(s) is/are true regarding Data Communication? Statements: I. Half duplex communication is multidirectional communication. II. Full duplex communication is bidirectional communication.
- A.
Only I
- B.
Only II
- C.
Both I and II
- D.
Neither I nor II
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Correct answer: B
Answer: Only II is correct.
Key idea: Half-duplex and full-duplex are both bidirectional (two-way). What separates them is timing — whether both ends can transmit at the same time — not the number of directions.
Simplex: one direction only (e.g., keyboard to computer).
Half-duplex: two-way (bidirectional), but the two ends take turns — only one transmits at a time (e.g., a walkie-talkie).
Full-duplex: two-way (bidirectional) and simultaneous — both ends transmit at the same time (e.g., a telephone call).
Why Statement I is false: Half-duplex is correctly described as bidirectional (two-way), not "multidirectional." "Multidirectional" is a non-standard, ambiguous term in this context; the standard textbook description of half-duplex is "bidirectional, but not simultaneous." Both half- and full-duplex are bidirectional, so directionality is not the distinguishing feature — timing is.
Why Statement II is true: Full-duplex supports two-way (bidirectional) communication, with the additional property that it happens simultaneously. Calling it bidirectional is accurate.