10 Question-Answer on line communications
1. Free space is an example of
(a) Unguided medium
(b) Guided medium
(c) Both (a) and (b)
(d) Neither (a) nor (b)
Ans: (a)
2. Out of guided media, maximum band width is of
(a) Twisted pair
(b) Co-axial cable
(c) Optical fiber
(d) None of the above.
Ans: ( c)
3. Point to point communication requires the use of
(a) A guided medium only
(b) Unguided medium only
(c) Any medium
(d) Neither
Ans: (a)
4. For a twisted pair, upper limit on the frequency is:
(a) 10 MHz
(b) 1 MHz
(c) 10 kHz
(d) 10 GHz
Ans: ( b)
5. For a twisted pair, upper limit on repeater spacing is:
(a) 6 km
(b) 60 km
(c) 600 km
(d) 6000 km
Ans: (a)
6. In co-axial cables, the repeater spacing is of the order of
(a) 20 km
(b) 2 km
(c) 200 km
(d) 2000 km
Ans: ( a)
7. Co-axial cables can carry
(a) Digital signals only
(b) Analog signals only
(c) Both digital and analog signals
(d) Neither digital nor analog signals
Ans: ( c)
8. The most commonly used two wire lines are
(a) Parallel wire lines
(b) Twisted pair wire lines
(c) Co-axial wire lines
(d) All the three above
Ans: (d)
9. The losses in transmission lines are
(a) Radiation losses only
(b) Conductor heating only
(c) Dielectric heating only
(d) All the three above
Ans: ( d)
10. Transmission lines become lossy at
(a) High frequencies
(b) Low frequencies
(c) Both at high and low frequencies
(d) Neither at high nor at low frequencies
Ans: ( a)