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)  13V                                      

B)  17V

C)  5V                         

D)         12V

Correct Answer: A

Solution :

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