Q. 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
Explanation
(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
$R\text{=}50 + 70 + 30 = 150\ \Omega$
Current in circuit, $I = \frac{V}{R} = \frac{3}{150} = 0.02\ A.$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.