According to the format of MIPS instruction architecture, how far can the program jump?

Answer 1

The MIPS jump instruction provides 26 bits of (unsigned) offset which, after shifting by 2 bits, results in a 28-bit (unsigned) offset. The high order 4 bits to form a full 32-bit are taken from the current IP. So, a jump instruction can jump to anywhere within a 4GiB/16 block of memory, or 256MiB space.