Derive the truth table for each of the following logic gates having two inputs.
(i)NOR gate
(ii)NAND gate
(iii)XNOR gate

i)
Assume inputs A and B and out C
Output is 1 when all inputs are 0

ii)
Assume inputs A and B and out C
Output is 1 when both inputs are not 1

iii)
Assume inputs A and B and out C
Produces output of 1 when both inputs are at same level