1. What is GAC? what are the uses it?
Ans. GAC stands for global assembly cache. It is an location or directory on the server where all the shared  assemblies are registered and which are reused in the application when needed.

2. Explain Machine.Config file ?
Ans. Machine.config file is a base configuration file for all .NET assemblies running  on the server. It specifies a settings that are global to a perticular machine.

3. Different types of authentication modes available in .NET?
Ans. Windows, Forms, Passport and None.

4. What exactly means strong name ?
Ans. Strong name is the unique name given to the assembly. It includes the following information,
     1.Assembely version,
     2.Public/Private Key token,
     3.Culture information
     4.ASsembely name

5. Where does the GAC exist ?
Ans. By defauit LocalDrive:\\assembly. Here local drive means where the operating  system is installed on your pc.
        e.g  BaseDrive:\winnt\assembly
              BaseDrive:\windows\assembly

6. Can you have two files with the same file name in GAC?
Ans. Yes, we can have fiels with same names.

7. What are the different types of variables availabe in .net and tell me about there scopes?
Ans.    Public - these types can be accessed anywhere
Private - these are accesssed within the same class
Protected - thsese are accessed winthin the same class and  also the class that inherites this class
Friend - all the members of the class within the assembly
Protected friend - all the members of assembely or inheriting class

8. what is dll hell?
Ans. Putting the same named dll files in a single directory but with different versions is known as dll hell.