Question

In the given figure, a diode 'D' is connected to an external resistance $R=100\Omega$ and an emf of $3.5V$. If the barrier potential developed across the diode is $0.5V$, the current in the circuit will be

• A. $35mA$
• B.
  $30mA$
• C.
  $40mA$
• D. $20mA$

Answer 1

The correct option is B

$30mA$
Net potential across the resistor is difference of the emf and the barrier potential.
$\therefore iR=\epsilon -V_{barrier}=3.5-0.5=3V$
$\Rightarrow i=\frac{3}{100}A=30\times {10}^{-3}A=30mA$.