Assume that each diode shown in the figure has a forward bias resistance of $50 \Omega$ and an infinite reverse bias resistance. The current through the resistance $150 \Omega$ is

• A

  $0.66 \mathrm{~A}$
• B

  $0.05 \mathrm{~A}$
• C

  zero
• Correct answer
  D

  $0.04 \mathrm{~A}$

Solution

In the circuit, diode $D_1$ is reverse biased and offers infinite resistance, diode $D_2$ is forward biased and offers $50 \Omega$ resistance. The equivalent circuit is shown in the figure. Total resistance of the circuit, $R=50 \Omega+50 \Omega+150 \Omega=250 \Omega$ The current in the circuit, $I=\frac{V}{R}=\frac{10 \mathrm{~V}}{250 \Omega}=0.04 \mathrm{~A}$ So, current through the resistance $150 \Omega$ is $0.04 \mathrm{~A}$.

Hence, the correct answer is option: 'D'.