Page 1081 - Basic Electrical Engineering

X NOT A
or X = A

The OR gate

The output of an OR gate is high if any of its inputs is high. An OR gate has

two or more inputs and one output. The Boolean expression for an OR gate is
written as
X = A or B

or,

X = A + B

The symbol and truth tables are shown below.

The AND gate

The output of an AND gate is high if all inputs are high, otherwise the output

is low. The AND gate has two or more inputs and one output. The Boolean
expression, truth table, and symbolic representation of an AND gate are

shown below.