question_answer

A diode having potential difference 0.5 V across its junction which does not depend on current, is connected in series with resistance of 20 \[\Omega \] across source. If 0.1 A current passes through resistance then what is the voltage of the source?

A)  1.5V                                     

B)  2.0V

C)  2.5 V                    

D)         5 V

Correct Answer: C

Solution :

The circuit diagram of the given situation is shown. Since, it is a closed mesh, the voltage is \[V=V+IR\] Given,   \[V=0.5\]volt,\[I=0.1\,\,A\],\[R=20\Omega \] \[\therefore \]  \[V=0.5+0.1\times 20\]                 \[V=2.5\]volt