Digital Electronics Objectives Part 07

121 . Common emitter amplifier is an inverter.
122 . A combination of AND function and NOT function results in NAND gate.
Question 123 to 127 refer to figure given below:

123 . Figure D corresponds to a NOR gate
124 . Figure A corresponds to OR gate.
125 . XNOR gate is represented by none of the four figures.
126 . Figure C represent XOR gate.
127 . Boolean expression for B is A.B=Y.
128 . It is required to determine the logical output of the circuit shown in figure, build using NAND gates. The correct answer is A + B

129 . Boolean expression for NAND gate is đ¨đŠ = Y.
130 . đ´+đĩ = Y is Boolean expression for NOR gate.
131 . The following truth table is for X-NOR gate.

132 . NAND gate is formed by inverting the out of the AND gate.
133 . OR gate corresponds to the action of parallel switches.
134 . The Boolean expression for the truth table given below will be C đŠA + CBđ¨ = Y
135 . The number of full adders in a 4-bit parallel adder will be three.
136 . A half adder includes a AND gate with XOR gate.
137 . For the circuit shown in Fig. 25 the output X is given by X= đ¨+ đŠ.

138 . A.đŠ = đ¨. đŠ is the correct relation.
139 . A logic circuit corresponding to â_ â is NOT gate.
140 . The variable in Boolean algebra can take one of the two possible values.