QUESTION 4 4.7. Which of the following responds to the Answer All 40 - PDF document

QUESTION 4 4.7. Which of the following responds to the Answer All 40 Questions request of a subscriber by sending a dial tone? 4.1. The physical connection between the ⃝ Line finder telephone set and the switching equipment is ⃝ First selector called the ⃝ Connector ⃝ Trunk line ⃝ Line equipment ⃝ Link 4.8. ______ is a voice operated device that inserts ⃝ Subscriber loop a high loss in the opposite direction of ⃝ Leased line transmission of the talking party. 4.2. The fixed telephone set is powered from the ⃝ Hybrid central office at ______ ⃝ 2-wire circuit ⃝ 42 to 52 Vdc ⃝ Echo suppressor ⃝ – 42 to -52 Vdc ⃝ VNL 4.9. ‘Time to Live’ is a field in _____ ⃝ 24 to 64 Vdc ⃝ – 24 to – 64 Vdc ⃝ Ethernet 4.3. What is an Erlang? ⃝ IPV4 ⃝ It is a unit of magnetic field intensity ⃝ IPV6 measured around a conductor ⃝ TCP ⃝ It is the number of erroneous bits received 4.10. The maximum intelligibility for voice per unit of time frequency is located between ⃝ It a unit of electrical energy radiated in ⃝ 250 and 500 Hz space. ⃝ 1000 and 3000 Hz ⃝ It is equal to the number of simultaneous ⃝ 500 and 1000 Hz calls originated during a specific hourly ⃝ 3000 and 5000 Hz period. 4.11. The maximum voice energy is located between 4.4. What is the local loop of a telephone system? ⃝ 250 and 500 Hz ⃝ It is a two-wire or four-wire ⃝ 1000 and 3000 Hz communication circuit between the ⃝ 500 and 1000 Hz customer’s premise and the central ⃝ 3000 and 5000 Hz office 4.12. Which of the following could be an Ethernet ⃝ It is a group of wires connecting a MAC address? telephone set to a modern ⃝ “250.76.4.4” ⃝ “04: A2:11:F6:2B:11 ” ⃝ It is a four-wire circuit connecting a facsimile machine to a computer ⃝ “04: A2:11:F6 ” ⃝ It is a single piece of wire connecting the ⃝ “250,76.4” subscriber’s telephone set to another 4.13. What is the s tandard telephone voice set in an adjacent room. channel spacing? ⃝ 44 MHz 4.5. The following field was introduced in IPv6, ⃝ 40 kHz i.e does not exist in IPv4 ⃝ 4 kHz ⃝ Traffic class ⃝ 40 MHz ⃝ Flag offset 4.14. Which tester is used to measure SWR? ⃝ Header Length ⃝ Multimeter ⃝ Diffserv ⃝ Oscilloscope 4.6. 1 mW is equal to ⃝ Spectrum analyzer ⃝ 90 dBm ⃝ Reflectometer ⃝ 0 dBm 4.15. To least the fault of the given line, a signal is ⃝ -30 dBm fed to the line, 30 µs later the signal ⃝ 120 dBm returned. What is the distance of the fault? ⃝ 9000 m ⃝ 300 m

⃝ 100 m ⃝ Skin effect ⃝ 4500 m 4.22. A device that converts a 2-wire circuit to a 4.16 . Which stage increases the selectivity of the 4-wire circuit. circuit in an AM receiver? ⃝ RS-232 interface ⃝ Detector ⃝ Hybrid circuit ⃝ IF stage ⃝ Balun ⃝ Modulator ⃝ Stub ⃝ Mixer 2.17. In virtual circuit network each packet 4.23. Which of the following is a frequency band contains of CT2 telephone? ⃝ 890 – 915 MHz ⃝ (a) full source and destination address ⃝ 824 – 849 MHz ⃝ (b) a short VC number ⃝ 1.48 – 1.50 GHz ⃝ (c) both (a) and (b) ⃝ 864 – 868 MHz ⃝ (d) none of the mention 4.18. The signal quality of the calls is constantly 4.24. How many simultaneous calls does each monitored by the base station, when the CT2 system can support? quality of the calls drops below a certain specified level. The base request the ⃝ 96 Mobile Telephone Switch Office (MTSO) ⃝ 20 to try and find a better cell site through a ⃝ 24 process known as ______ ⃝ 49 ⃝ Hand-off ⃝ Cell splitting 4.25. How many simultaneous calls does a CT2 ⃝ Roaming radio transceiver can assess at any given time? ⃝ Frequency reuse ⃝ 40 2.19. Ethernet. In an Ethernet network, which of ⃝ 80 the following are true: ⃝ 32 ⃝ Ethernet switches learn addresses by looking ⃝ 8 at the destination address of packets as they pass by. 4.26. The AGC voltage of a radio receiver is ⃝ Ethernet hubs and repeaters learn addresses always _______. by looking at the addresses of packets as they ⃝ Present before adjustments can be made pass by. ⃝ DC, but may have either polarity positive ⃝ A correctly operating Ethernet switch never DC sends a packet to the wrong outgoing port. ⃝ Positive DC ⃝ Ethernet switches (a.k.a bridges) learn ⃝ Negative addresses by looking at the source address of packets as they pass by. 4.27. What is a concentrator? 2.20. What transmission rate is needed to transmit ⃝ A system that improves the signal-to- a 4" x 6" photograph (uncompressed, and with a noise ratio by compressing the resolution of 1200 dots per inch and 24 bits per volume range of a signal. pixel) in 1 second? ⃝ A device that varies the characteristics of ⃝ 28.8kb/s a carrier signal in accordance with the ⃝ 28.8kbits waveform of a modulating signal ⃝ 8.29Mb/s which contains useful information ⃝ 829Mb/s ⃝ A switching system that lets a large 4.21. The _______ in an FM receiver causes a number of telephone or data stronger signal to dominate over a weaker processing subscribers use a lesser signal on the same frequency. number of transmission lines or a ⃝ Capture effect narrow bandwidth ⃝ Flywheel effect ⃝ Equipment in the central office. ⃝ Hall effect

4.28. What is a leased line? 4.35. The circuit that performs demultiplexing in ⃝ A piece of wire used in a local area an FDM system is _____. network in one building ⃝ Op - Amp ⃝ A piece of wire connecting a telephone ⃝ Bandpass filter set to a PABX ⃝ Discriminator ⃝ A temporary connection of one computer ⃝ Subcarrier oscillator to a mainframe via a modern and a 4.36. What is the bandwidth required to transmit telephone line at a rate of 10 Mbps in the presence of a 28-bd ⃝ A permanent circuit for a private use S/N ratio? within a communication network ⃝ 1.075 MHz ⃝ 10 MHz 4.29. Analogue radio communications between ⃝ 5 MHz points using a single share frequency is ______ ⃝ 10.5 MHz ⃝ Simplex 4.37. T1 stands for ⃝ Full duplex ⃝ Transmission one ⃝ Half-duplex ⃝ Telecommunication one ⃝ Full/full duplex ⃝ Telex one ⃝ Transmission line one 4.30. What is the number of channels of a cellular 4.38. How long is IPv6 address? system with an allocated spectrum of 25 MHz and ⃝ 32 bits with a channel of 30 kHz bandwidth? ⃝ 128 bytes ⃝ 833 ⃝ 64 bits ⃝ 240 ⃝ 128 bits ⃝ 1000 4.39. Which of the following is private IP ⃝ 666 addresses ⃝ 12.0.0.1 4.31 Geographic National Destination Codes in ⃝ 168.172.19.39 Kenya have _____ digits. ⃝ 172.20.14.36 ⃝ 4 ⃝ 192.168.24.43 ⃝ 3 ⃝ 2 4.40. The first commercial cellular mobile system ⃝ 5 was first operated in ______ ⃝ 1979 4.32 The international country calling code of ⃝ 1981 China starts with which digit? ⃝ 1983 ⃝ 8 ⃝ 1985 ⃝ 9 ⃝ 6 ⃝ 7 4.33. Which of the following is equal to the reciprocal of the sample rate in T1? ⃝ Slot Time ⃝ Transmission time ⃝ Frame time ⃝ Bit rate 4.34. What is the final output of a multiplexer? ⃝ Baseband ⃝ Composite baseband ⃝ Information ⃝ Composite carrier