question_answer

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

A)  30mA                  

B)  40mA  

C)  20mA                  

D)  35mA

Correct Answer: A

Solution :

Given, external resistance R = 100\[\Omega \] and an emf is 3.5V. Potential barrier across the diode is 0.5 V, Potential difference on \[R=3.5V-0.5V=3.0V\] Current in circuit, \[I=\frac{V}{R}=\frac{3}{100}=0.03A=30mA\]