Answer to Question #208772 in Electric Circuits for shakeelafridim1234

Question

The sine wave represents Voltage Eab across the terminal a, b of an AC motor that operates at 50 Hz. Knowing that 0=30 and Em = 100V, find the voltage at t=0 and t= 27.144 S.

Answer 1

As per the given question,

The voltage at t= 0 is,

$E_{ab}=E_m \cos(360ft+\theta)$

Now, substituting the values,

$=100\cos(360\times 50\times0+30^\circ)$ V

$=100\cos(30^\circ)$ V

$=86.6V$

The voltage at t= 27.144

$\Rightarrow E_{ab}=100\cos(360\times 50\times 27.144+30^\circ)$

$\Rightarrow E_{ab}=100\cos(488622^\circ)$

$\Rightarrow E_{ab}=-20.8V$