Question

The circuit shown in the figure contains two diodes each with a forward resistance of $30\Omega$ and with infinite backward resistance. If the battery is $3V$, the current through the $50\Omega$ resistance (in ampere) is

• A. zero
• B. $0.01$
• C. $0.02$
• D. $0.03$

Answer 1

Answer: (C)

In the circuit the upper diode $D_1$ is reverse biased and the lower diode $D_2$ is forward biased. Thus there will be no current across upper diode junction. The effective circuit will be as shown in figure.
Total resistance of circuit,
$R=50+70+30=150\Omega$
Current in circuit,
$I=\frac{V}{R}$
$=\frac{3V}{150\Omega }$
$=0.02A$