Two diodes of silicon and germanium are connected in series as shown below. The current flowing through the circuit will be around

• A

  0
• Correct answer
  B

  3 A
• C

  4 A
• D

  3.5 A

Solution

We know that, barrier potential of $\mathrm{Ge}, V_{B_1}=0.3 \mathrm{~V}$ and barrier potential of $\mathrm{Si}, V_{B_2}=0.7 \mathrm{~V}$ Redrawing the given figure as

Applying KVL, we get
$\begin{array}{ll} <br/>& 10-0.3-I \times 1-0.7-2 \times I=0 \\<br/>\Rightarrow \quad & 3 I=9 \Rightarrow I=3 \mathrm{~A}<br/>\end{array}$

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