The following configuration of the logic gate is equivalent to

1.  NAND gate

2.  XOR gate

3.  OR gate

4.  NOR gate

To get output 1 for the following circuit, the correct choice for the input is

(1) $A=1, B=0, C=0$       

(2) $A=1, B=1, C=0$

(3) $A=1, B=0, C=1$       

(4) $A=0, B=1, C=0$

The output (x) of logic circuit shown in figure will be 

(1) $X=\stackrel{=}{A}·\stackrel{=}{B}$

(2) $X=\overline{A.B}$

(3)$X=A·B$

(4)$X=\overline{A+B}$

The figure shows a logic circuit with two inputs A and B and the output C.The voltage wave forms across A, B and C are as given.The logic circuit gate is 

1. OR gate                                          2. NOR gate

3. AND gate                                        4. NAND gate

Symbolic representation of four logic gates

are shown as

(i) 

(ii) 

(iii) 

(iv) 

Pick out which ones are for AND, NAND and 

NOT gates, respectively.

1. (iii), (ii)and (i)

2. (iii), (ii) and (iv)

3. (ii), (iv) and (iii)

4. (ii), (iii) and (iv)