### 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.**