Explain the difference between value types and reference types

Correct Answer: Wi-Fi technology is a technology used for transmitting a signal using the 80211 specifications works a lot like it does with a basic Ethernet hub: They?re both two-way forms of communication, and they both use the same frequency to both transmit and receive, often referred to a half-duplex WLANs used radio frequencies (RFs) that are radiated into the air from an antenna that creates radio waves These waves can be absorbed, refracted, or reflected by walls, water, and metal surfaces, resulting in low signal strength So because of this vulnerability to surrounding environmental factors, it?s pretty apparent that wire-less will never offer us the same robustness as a wired network can, but that still doesn?t mean we?re not going to use or run the wireless or Wi-Fi

Correct Answer: Basically there are many standards of Wi-Fi in the industry but some popular of them are 80211a, 80211b, 80211g/n With the support of these Wi-Fi protocols we can communicate/interact among the devices at the speed of 5Ghz to 24Ghz dual band communication If we have Wi-Fi nic card so firstly we have to install their drivers and after installation if we have Wi-Fi access point then we can see the signal strength in the right corner below just open that and find the access point to connect, if access point is configured with the security, type the key to connect and enjoy the service Wi-Fi is technically referred to as the 80211 protocol Over time, Wi-Fi has improved, giving rise to different variations of the protocol 80211a ? This version operates at 54Mbps It is considered as the favorite wireless LAN protocol for IP telephony

Correct Answer: Advantages of 3G: - Overcrowding is relieved in existing systems with radio spectrum - Bandwidth, security and reliability are more - Provides interoperability among service providers - Availability of fixed and variable rates - Support to devices with backward compatibility with existing networks - Always online devices ? 3G uses IP connectivity which is packet based - Rich multi media services are available Disadvantages of 3G: - The cost of cellular infrastructure , upgrading base stations is very high - Needs different handsets - Roaming and data/voice work together has not yet been implemented - Power consumption is high - Requires closer base stations and are expensive - Spectrum-license costs, network deployment costs and handset subsidies subscribers are tremendous

Correct Answer: The handheld device is used as a network device, which always connected to the data account of the user via redirector software The software is installed on the BlackBerry Enterprise Server The communication between the software, BE Server and the hand held device?s software is always a two-way street BES immediately updates the mobile device or the email or the calendar account, whenever a change in email account occurs The push technology of BlackBerry keeps the device instantly in ?synch? without any effort by the user

Correct Answer: Research in Motion, a Canadian company provided a proprietary operating system for BlackBerry The operating system provides support for Java MIDP 10 and WAP 12 The current version supports Novell Group Wise and Lotus Notes Third-party software can be developed using BlackBerry APIs as well, with certain restriction functionality must be signed by RIM digitally, so that it can be associated to a developer account

Correct Answer: The Net runtime knows about all the references between the objects It can identify all the circular references that are reachable from the root and hence finalize them to free them all at once if and when needed

Correct Answer: Delegates

Explanation:

A delegate declares a ref type that references a named of anonymous method. Delegates are secure and type-safe.

Correct Answer: All the above

Explanation:

All the above listed are debugging windows in .NET

Correct Answer: The Net runtime knows about all the references between the objects It can identify all the circular references that are reachable from the root and hence finalize them to free them all at once if and when needed

Correct Answer: A keyword that specifies that types in a particular nemespace can be referred to without requiring their full qualified type names 'using' reserved word always come with namespaces eg using systems so because of this useful classes supplied by Microsoft which are contained by system namespace are availble for user