Question

A 2 $V$ battery is connected across the points A and B as shown in the figure given below. Assuming that the resistance of each diode is zero in forward bias and infinity in reverse bias, the current supplied by the battery when one of the diodes has its positive terminal is connected to $A$ (as shown in figure) is

• A. $0.2A$
• B. $0.4A$
• C. $0$
• D. $0.1A$

Answer 1

The correct option is A $0.2A$

Since diode in upper branch is forward biased and in lower branch it is reverse biased.So no current flows through the lower diode. Hence the current through the circuit is given by
$i=\frac{V}{R+r_d}{r}_d=\mathrm{diode}\mathrm{resistance}\mathrm{in}\mathrm{forward}\mathrm{biasing}=0\mathrm{which}\mathrm{gives}\mathrm{us},i=\frac{V}{R}=\frac{2}{10}=0.2A$