Identify the logic operation performed by the given circuit:

 

To measure light intensity we use

The Boolean equation for the circuit as shown in figure is

 

The resistance of a silicon junction diode, whose V - I characteristics is as shown in figure is (V_k = 0.7 V)

Two rain drops reach earth from clouds with different terminal velocities having ratio 9 : 4. Then the ratio of their volumes is

In the voltage regulator circuit shown below, the reverse breakdown voltage of zener diode is 3 V. Find the current through zener diode.