14.14 Write the truth table for circuit given in Fig. 14.39 below consisting of NOR gates and identify the logic operation (OR, AND, NOT) which this circuit is performing.

(Hint: A = 0, B = 1 then A and B inputs of second NOR gate will be 0 and hence Y=1. Similarly work out the values of Y for other combinations of A and B. Compare with the truth table of OR, AND, NOT gates and find the correct one.)

The current flow through the resistance in the given circuit is : (Cut-off voltage for both diodes is 0.7 V)

A n-p-n transistor can be used as

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

 

In the above diagram, balance length for E' is ℓ₀. If cross sectional area of wire AB is doubled then what will be new balancing length ?

The figure shows a logic circuit with two inputs A and B and an output C. The voltage wave forms of A, B and C are as given, then logic circuit will be equivalent to :-