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The BTCS exam has 50 questions and runs 2 hours.
These 10 free BTCS questions are organized by exam domain, so you can see how each part of the Broadband TelecomCenter Specialist blueprint is tested. Reveal the answer and explanation under each question.
A qualified specialist is preparing to expose terminals in a headend DC distribution cabinet. The rectifier AC feeders are locked out, but the battery string remains connected. The cabinet's bus-voltage indicator is dark. What is required before the cabinet can be treated as deenergized?
Correct answer: B - Complete source isolation and stored-energy control, then verify absence of voltage.
A transmitter launches +4 dBm into a fiber link containing 6 km of fiber at 0.25 dB/km, two connector pairs at 0.5 dB per pair, and five splices at 0.1 dB each. There are no other path losses. The receiver's permitted input range is -18 to -3 dBm, and commissioning requires at least 3 dB of margin above sensitivity. Which fixed optical attenuator meets both requirements?
Correct answer: C - 6 dB
After additional carriers are activated, a headend amplifier's per-channel input levels remain unchanged. Several 256-QAM channels now have lower MER and new intermodulation products at its output, although those channels are clean at its input. Adding attenuation only at the analyzer input does not improve MER. Which adjustment addresses the impairment?
Correct answer: C - Reduce the composite RF drive into the amplifier.
On a legacy NTSC path, a source specified to deliver 1.0 V peak-to-peak into 75 ohms reads about 2.0 V peak-to-peak on a loop-through waveform monitor. Sync-to-white proportions remain normal. The monitor input is high impedance, and its final loop-through connector is open. How should the reading be checked before changing source gain?
Correct answer: C - Place one 75-ohm termination at the end of the loop-through path.
Newly rebooted cable modems complete downstream acquisition, initial ranging, and IPv4 DHCP, but time out while downloading their configuration files. A new firewall permits requests to UDP port 69 and permits server replies only when their source is also UDP port 69. The TFTP server receives the requests. Which protocol behavior explains the stalled initialization?
Correct answer: A - The server sends file data from a separately selected UDP transfer port.
Program 214 is unencrypted and has normal video but no audio after remultiplexing. The output contains: PAT: program 214 -> PMT PID 0x0100. PMT: video PID 0x0200; audio PID 0x0201. Payload: valid video on 0x0200; codec-compatible audio on 0x0231; no packets on 0x0201. The audio assignment to 0x0231 is intentional. Which table change restores automatic audio selection?
Correct answer: B - Change the PMT's audio elementary-stream PID to 0x0231.
Multicast video on a switched VLAN returns immediately when a receiver rejoins, then disappears several minutes later. Unicast management remains available. IGMP snooping is enabled; a capture shows membership reports but no queries, and multicast forwarding entries age out. What will stabilize delivery while preserving membership-based forwarding?
Correct answer: D - Enable an IGMP querier on this VLAN.
In a PacketCable 2.0 call, SIP signaling reaches 200 OK and ACK. The far-end party hears the cable subscriber, but the subscriber hears silence. A capture at the eMTA shows transmitted RTP and no received RTP; its FXS port passes a local handset test. Where should the specialist trace the missing speech?
Correct answer: A - Along the inbound RTP path, using the receive address and port negotiated in SDP.
A return-path fault produces millisecond bursts of uncorrectable codewords. Averaged spectrum traces look clean between incidents. The specialist must identify which frequencies are occupied during each burst, not merely confirm that errors occurred. Which acquisition method is most informative?
Correct answer: D - Capture a time-correlated spectrum of the bursts using peak detection and max hold.
A legacy DOCSIS upstream scheduler must carry fixed-rate voice packets of equal size at regular intervals, with no silence suppression. The design calls for periodic transmission opportunities without a fresh bandwidth request for each packet. Which scheduling service fits that requirement?
Correct answer: A - Unsolicited grant service (UGS)
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