Telecom Cable MCQ

Telecom Cable MCQ

S.No. Question Answer

1. The cable should be laid in ________ pipes on either side of a 

Traction Sub-station 

a) GI pipe b) RCC pipe c) PVC pipe d) none of the three 

(b)

2. Permissible psophemetric voltage in RE cable is not more than ____

a) 1mV b) 3mV c)1.5mV d)2 mV

(d)

3. Transmission loss of Copper wire 0.9mm dia (unloaded)

a) 0.56 dB/Km c) 0.63 dB/Km

b) 0.25 dB/Km d) None/Km

(c)

4. Codal life of 6 quad cables 

a) 5 years b) 6 years c) 10 years d)20 years 

(d)

5. Loop resistance of 6 quad cable

a) 65 Ω/Km b) 56 Ω/Km c) 20 Ω/Km d)None

(b)

6. Cable Markers are provided at every _____ meters 

a) 40 b) 100 c)50 d)60

(c)

7. Emergency control runs over which quad no.

a) 4 b)1 c)3 d)2

(c)

8. Fiber loss/km at 1550 nanometer is _______

a)0.4 dB/km b)0.35dB/km c)1.5dB/km d)0.25dB/km

(d)

9. The primary purpose of Aluminium screen in 6 Quad cable is to 

provide –

(A) mechanical protection (B) reduction in induced voltages 

(C) protection from rats (D) protection from acidic soil

(b)

10. Characteristic impedance of PIJF pair cable is

a) 600 ohms B) 1120 ohms C) 470 ohms D) 56 ohms

(a)

11. Screening in underground cables is done to reduce

a) Noise b) cross talk c) TX loss d) induced voltage

(d)

12. Supply voltage required for CCEO system is

a)48V b)24V c)12V d)-48V

(d)

13. Maximum no. of control telephones a MTWE can have 

a)4 b)5 c)10 d)6

(a)

14. Loss in case of fusion splicing should be less than _____dB.

a) 0.1 dB b) 5 dB

c) 1 dB d) 0.5 dB

(a)

15. Twisting of cables is done for _________ in cables

a) Balancing b) reducing Interference

c) reducing cross talk d) earthing

(c)

Earthing & Surge Protection

1. Railway telecom earth should have a value of –

a) Less than 10 ohms c) Less than 2 ohms

b) Less than 1 ohm d) None of the above

(b)

2. Which of the following is the most corrosion resistant

a) Mild steel c) Copper

b) Cast iron d) Galvanised mild steel

(c)

3. Which of the following is not a suitable place for placing earth

electrode?

a) Marshy ground c) Clayey soil

b) Loamy soil d) River bed

(d)

4. Which of the following is Earth enhancement material is 

a) Bentonite c)Bonding Resins

b) Graphite & Portland d) All of the above 

(d)

5. In CLASS-C protection SPD is provided between ___________. 

a) Phase & neutral c)Phase & Earth

b) Neutral & Earth d) External Power supply

(a)

6. Resistivity of wet, moist and dry soil is _________Ohm/meter.

a) 100,1000,5000 c)10, 100, 1000

b) 500, 100, 1000 d)10, 500, 1000

(c)

7. MOV and GAS DISCHARGE TUBES are used in _____protection.

a) CLASS-D c) CLASS-B

b) CLASS-A d) CLASS-C

(a)

8. Earth is a ___________

a) Good conductor b) Bad conductor

c) Equipotential surface d) None of the above

(c)

9. Characteristics of good earthing system are-

a) Excellent Electrical Conductivity b)High Corrosion Resistance

c) Mechanically Robust and Reliable. d) All of the above

(d)

10. The minimum distance between any two earth is _______

a) 5m b) 6m c) 2.5m 3) 3m

(d)

11. Surge protection device Rating is 50KA (10/350 micro seconds)

means, 50KA indicates max. Surge Current,10 micro seconds is time

taken to reach _______and 350micro seconds is time taken

to fall to the_________.

Peak 

value, 

half 

peak 

value

PDH - MUX

1. What is the output rate and no. of time slots in a MUX

a) 1.024 Mbps, 30 time slots b) 2.048 Mbps, 32 time slots

c) 2.048 Mbps, 30 time slots c) 1.024 Mbps, time slots

(b)

2. Conference card provides _____ simultaneous conference at a time

a) 12 b) 10 c) 20 d) 15

(d)

3. 

Interface available in a MUX are –

a) 4 W/2 W E&M. b) Subscriber interface/ Hot line interface.

c) Exchange interface. d) All of the above 

(d)

4. Webfil MUX has _____ no. of total slots, dedicated slot for NIM & 

Tributary module are _____ & ______

a) 13, 3 & 4 b) 13, 2 & 3

c) 14, 2 & 3 c) 14,3 & 4 

(a)

5. ______ wires are required for IN/OUT of a channel in PD MUX

a) 32 b) 64 c) 30 d)60

(b)

6. KLM of 31st E1 is ____________

a) 1-4-1 b)1-3-1

c) 2-4-1 d)2-4-5

(c)

7. For branching in STM ______ card is used

a) TET b)TEX

c) LI d) Control

(c)

8. Bit rate of STM-1 is ________

a) 155.520 M bit/s. b) 155.520 bps

c) 139.264 Mbps d) 139.264 bps

(a)