Question

A 50 Hz ac source of 20 volts is connected across R and C as shown in figure. The voltage across R is 12 volt. The voltage across C is –

• A. 8 V
• B. 16 V
• C. 10 V
• D. Not possible to determine unless values of R and C are given

Answer 1

Answer: (B)

16 V

Answer 2

V_source = $\sqrt{V_{R}^{2} + V_{C}^{2}}$

\ V_C = $\sqrt{V_{Source}^{2}–V_{R}^{2}}$

= $\sqrt{(20)^{2}–(12)^{2}}$

= 16 V