Can you call one constructor from another, If a class has multiple constructor?

Yes, Use this() syntax.

What is the difference between checked and unchecked exception?

What is JVM?

A Java virtual machine (JVM) is an abstract computing machine that enables a computer to run a Java program.

JVM is a platform-independent execution environment that converts Java bytecode into machine language and executes it.

JVMs are available for many hardware and software platforms (so JVM is platform dependent).

The Java Virtual Machine is responsible for interpreting Java bytecode, and translating this into actions or operating system calls.
For example, a request to establish a socket connection to a remote machine will involve an operating system call. Different operating systems handle sockets in different ways - but the programmer doesn't need to worry about such details.  It is the responsibility of the JVM to handle these translations, so that the operating system and CPU architecture on which Java software is running is completely irrelevant to the developer.

What is the actual use of interface in Java?

What is the main benefit of using Generics?

The main objective of generics is to provide type safety and to resolve type casting problems.