VDV Copper Cabling 2 — Questions and Answers
Question 1: What is the maximum segment length for Cat5e horizontal cabling under TIA-568 standards?
- 90 meters (Correct answer)
- 100 meters
- 110 meters
- 120 meters
Correct answer: 90 meters
TIA-568 limits horizontal permanent link runs to 90 meters, reserving 10 meters for patch cords to reach the 100-meter channel maximum.
Question 2: Which pair is used for data transmission in a standard 10BASE-T Ethernet connection using T568B wiring?
- Pairs 1 and 2 (pins 1,2 and 3,6) (Correct answer)
- Pairs 2 and 3 (pins 4,5 and 7,8)
- Pairs 1 and 4 (pins 1,2 and 7,8)
- Pairs 3 and 4 (pins 3,6 and 4,5)
Correct answer: Pairs 1 and 2 (pins 1,2 and 3,6)
10BASE-T uses pins 1,2 (transmit) and 3,6 (receive), which correspond to pairs 2 and 3 in T568B color coding.
Question 3: What does the term 'NEXT' measure in copper cabling performance testing?
- Near-End Crosstalk between adjacent pairs at the transmitting end (Correct answer)
- Network Extension Transmission level
- Noise Equivalent Transfer in signal testing
- Near-End Transmission level at the far end
Correct answer: Near-End Crosstalk between adjacent pairs at the transmitting end
NEXT (Near-End Crosstalk) measures the unwanted signal coupling between pairs at the same end where the test signal is injected.
Question 4: A technician is pulling Cat6 cable through conduit and encounters significant resistance. What is the maximum recommended pulling tension for Cat6 UTP cable?
- 110 N (25 lbf) (Correct answer)
- 220 N (50 lbf)
- 440 N (100 lbf)
- 670 N (150 lbf)
Correct answer: 110 N (25 lbf)
TIA-568 specifies a maximum pulling tension of 110 N (25 lbf) for 4-pair UTP cable to prevent stretching or damaging the conductors.
Question 5: Which type of copper cable uses a metallic foil shield around each individual pair as well as an overall braid shield?
- S/FTP (SFTP) (Correct answer)
- U/UTP
- F/UTP
- U/FTP
Correct answer: S/FTP (SFTP)
S/FTP cable has individually foil-shielded pairs (FTP) plus an overall braided shield (S/), providing maximum EMI protection.
Question 6: What is the minimum bend radius for a 4-pair Cat6 UTP cable during installation?
- 4 times the cable diameter
- 8 times the cable diameter (Correct answer)
- 10 times the cable diameter
- 2 times the cable diameter
Correct answer: 8 times the cable diameter
TIA-568 recommends a minimum bend radius of 8 times the cable outer diameter for 4-pair UTP during installation to prevent pair damage.
Question 7: A cable test fails for 'Return Loss.' What does this indicate?
- Excessive signal reflected back due to impedance mismatches along the cable (Correct answer)
- Signal loss from a broken conductor
- Crosstalk between pairs at the far end
- Resistance too high at the cable termination
Correct answer: Excessive signal reflected back due to impedance mismatches along the cable
Return Loss measures how much signal is reflected back toward the source due to impedance discontinuities such as poor terminations or kinks.
VDV Copper Cabling 2
What is the maximum segment length for Cat5e horizontal cabling under TIA-568 standards?