In the Direct Addressing Mode, the address part of the instruction is equal to the effective address. Here, the operand resides in the memory. Register address is given directly by the address field of the instruction. Hence, Effective Address = 400.
In the Immediate Addressing Mode, when the instruction is assembled, the operand comes immediately after the opcode and as such, data is a part of the instruction itself. Hence, Effective Address = 301.
In the Relative Addressing Mode, the Program Counter (PC) is the implicitly referenced register. So, the effective address is generated by adding the next instruction address to the the address field. Hence, Effective Address = 302 + 400 = 702.
In the Register Indirect Addressing Mode, the operand (which is the contents of a register) is specified by giving the name of the register (in this case, the processor register) in the instruction. Hence, Effective Address = 200.
In the Indexed Register Addressing Mode, the effective address is the sum of the contents of 2 registers. Since, R1 here acts as the index register and the address field contains the value 400, hence Effective Address = 200 + 400 = 600.
