CISCO考试的一些demo

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Exam CISCO 642-831 Demo　　1.EIRP is a measurement typically calculated in _____.646-573
　　A: dBl
　　B: dBr
　　C: dBd
　　D: dBm
　　Correct Answers:  D642-551
　　2.Which antenna provides the most flexibility at the central location of a point-to-multipoint bridging application?1z0-101
　　A: isotropic antenna
　　B: 12 dBi omni-directional
　　C: 23 dBi grid dish antenna
　　D: 21 dBi parabolic dish antenna
　　Correct Answers:  B70-630  70-281  70-631
　　3.When doing a survey in a hospital application, which three should you consider? (Choose three.)050-692
　　A: pagers
　　B: fire doors
　　C: televisions
　　D: microwave ovens
　　E: radiology/x-ray areas
　　Correct Answers:  B, D, EHP0-764
　　4.What is the maximum Ethernet run from the Cisco Aironet 1400 Series Bridge to the switch or router?000-636
　　A: 10 km (maximum distance for single mode fiber)
　　B: 100 meters (maximum distance for Fast Ethernet)
　　C: 500 meters (Cisco Aironet 1400 Series uses a hybrid Ethernet/fiber interface.)
　　D: 200 meters (100 meters from Switch to Power Injector, then another 100 meters to Bridge Outdoor Unit (ODU)
　　Correct Answers:  D MB5-198  MB3-234
　　5.What does the 802.11g protection mechanism do? MB4-161  MB3-412
　　A: uses the CTS (clear to send) to manage the transmit power of all clients
　　B: reduces the data rate for 802.11g clients when 802.11b clients are in the same cell
　　C: reduces the transmit power of 802.11b clients when 802.11g clients are in the same cell
　　D: uses CTS (clear to send) to protect 802.11g clients from collisions with 802.11b clients
　　Correct Answers:  DMB6-291  MB3-006
　　6.Why are diversity antennas used indoors?MB2-421

　　A: They are smaller in>　　B: They are designed to handle multi-path.
　　C: They have lower transmit signal strength than standard antennas.
　　D: They have higher transmit signal strength than standard antennas.
　　Correct Answers:  BMCSE
　　7.Which specific antenna architecture is used to help eliminate RF null areas of coverage?
　　A: splitters
　　B: diversity
　　C: high gain omni
　　D: patch antennas
　　Correct Answers:  B70-631
　　8.What is the purpose of the WPA 4-way handshake?
　　A: authenticates users
　　B: negotiates broadcast keys
　　C: derives WPA unicast keys
　　D: negotiates the encryption cipher types
　　Correct Answers:  CHP0-053
　　9.Which statement is true about the Cisco Aironet 1400 Series Bridge?
　　A: It does not support wireless clients.
　　B: It supports wireless clients only on a root bridge per IEEE specification.
　　C: It supports wireless clients only on a non-root bridges with valid links to a root bridge.
　　D: It supports wireless clients on a root bridge when a wireless client MAC address is set to forward.
　　Correct Answers:  A1z0-043
　　10.Which statement about non-overlapping channels is true?HP0-239 HP0-762
　　A: Non-overlapping channels share the same frequencies to improve roaming.
　　B: Non-overlapping channels use different frequency bands to improve roaming.
　　C: Non-overlapping channels share the same frequencies but use different modulations to avoid interference.
　　D: Non-overlapping channels use the same frequency band but use non-shared frequencies to avoid interference.
　　Correct Answers:  D310-560 310-615