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 W across source. If 0.1 A passes through resistance then what is the voltage of the source [DCE 2005]

A)            1.5 V                                        

B)            2.0 V 

C)            2.5 V                                        

D)            5 V

Correct Answer: C

Solution :

                   \[V'=V+IR\] = 0.5 + 0.1 ´ 20 = 2.5 V