question_answer

A resistor and a capacitor are connected in series with an AC source. If the potential drop across the capacitor is 5 V and that across resistor is 12 V, then applied voltage is

A)  13 V                                     

B)  17 V

C)  5 V                                        

D)  12 V

Correct Answer: A

Solution :

Let the applied voltage be V volt. Here, \[{{V}_{R}}=12\,V,\,{{V}_{C}}=5\,V\] \[\therefore \]  \[V=\sqrt{V_{R}^{2}+V_{C}^{2}}=\sqrt{{{(12)}^{2}}+{{(5)}^{2}}}\]                 \[=\sqrt{144+25}=\sqrt{169}=13\,\,V\]