Wireless LANs Electronic Mail and File Transfer
Subject: Computer Networks
Sample Practice Questions
Question 1: What is the access point (AP) in a wireless LAN?
- device that allows wireless devices to connect to a wired network
- wireless devices itself
- both device that allows wireless devices to connect to a wired network and wireless devices itself
- all the nodes in the network
Explanation: Access point in a wireless network is any device that will allow the wireless devices to a wired network. A router is the best example of an Access Point.
Question 2: In wireless ad-hoc network _________
- access point is not required
- access point is must
- nodes are not required
- all nodes are access points
Explanation: An ad-hoc wireless network is a decentralized kind of a wireless network. An access point is usually a central device and it would go against the rules of the ad-hoc network to use one. Hence it is not required.
Question 3: Which multiple access technique is used by IEEE 802.11 standard for wireless LAN?
- CDMA
- CSMA/CA
- ALOHA
- CSMA/CD
Explanation: CSMA/CA stands for Carrier-sense multiple access/collision avoidance. It is a multiple access protocol used by IEEE 802.11 standard for wireless LAN. It’s based on the principle of collision avoidance by using different algorithms to avoid collisions between channels.
Question 4: In wireless distribution system __________
- multiple access point are inter-connected with each other
- there is no access point
- only one access point exists
- access points are not required
Explanation: A Wireless Distribution System allows the connection of multiple access points together. It is used to expand a wireless network to a larger network.
Question 5: A wireless network interface controller can work in _______
- infrastructure mode
- ad-hoc mode
- both infrastructure mode and ad-hoc mode
- WDS mode
Explanation: A wireless network interface controller works on the physical layer and the data link layer of the OSI model. Infrastructure mode WNIC needs access point but in ad-hoc mode access point is not required.
Question 6: In wireless network an extended service set is a set of ________
- connected basic service sets
- all stations
- all access points
- connected access points
Explanation: The extended service set is a part of the IEEE 802.11 WLAN architecture and is used to expand the range of the basic service set by allowing connection of multiple basic service sets.
Question 7: Mostly ________ is used in wireless LAN.
- time division multiplexing
- orthogonal frequency division multiplexing
- space division multiplexing
- channel division multiplexing
Explanation: In orthogonal frequency division multiplexing, digital data is encoded on multiple carrier frequencies. It is also used in digital television and audio broadcasting in addition to Wireless LANs.
Question 8: Which one of the following event is not possible in wireless LAN?
- collision detection
- acknowledgement of data frames
- multi-mode data transmission
- connection to wired networks
Explanation: Collision detection is not possible in wireless LAN with no extensions. Collision detection techniques for multiple access like CSMA/CD are used to detect collisions in Wireless LANs.
Question 9: What is Wired Equivalent Privacy (WEP)?
- security algorithm for ethernet
- security algorithm for wireless networks
- security algorithm for usb communication
- security algorithm for emails
Explanation: WEP is a security algorithm for wireless network which intended to provide data confidentiality comparable to that of traditional wired networks. It was introduced in 1997.
Question 10: What is WPA?
- wi-fi protected access
- wired protected access
- wired process access
- wi-fi process access
Explanation: WPA or WiFi Protected Access is a security protocol used to provide users and firms with strong data security and protection for their wireless networks (WiFi) to give them confidence that only authorized users can access their network.