Question

The instantaneous potential difference between points A and B is (Phase angle is ${37}^0$)

• A. $8\sin (50\pi t+37\frac{\pi }{180})$
• B. $8\sin (50\pi t-37\frac{\pi }{180})$
• C. $10\sin \left(50\pi t\right)$
• D. $10\cos \left(50\pi t\right)$

Answer 1

Answer: (B)

$8\sin (50\pi t-37\frac{\pi }{180})$

Impedance $z=\sqrt{(8-2{)}^2+(8{)}^2}=10\Omega$

current lags voltage by ${37}^{\circ }$,then

$i=\frac{10}{10}\sin (50\pi t-{37}^{\circ })$

$V_{AB}=i\times R=8\sin (50\pi t-{37}^{\circ })$