what combination of input levels should you apply to the gat

what combination of input levels should you apply to the gate\'s inputs to determine which type of gate it is?

Solution

Que : what combination of input levels should you apply to the gate\'s inputs to determine which type of gate it is ?

Ans :
       let say the inputs are A and B.
let look at the truth tables for AND and OR gate

type A B AND OR
----- -- -- --- ---  
1 0 0 0 0
   2       1 0 0 1
   3       0 1 0 1
   4       1 1 1 1

   Combination to be tested will be -- type4 ,type3, type2

type3 type4 type2 gate
---- --- ---- ---
1 0 AND
1 1 OR  
0 1 1 XOR  

For gate to be identified as AND or OR gate , type2 output will not matter.