1. Identify that \( V_p = 300\,V \) and the angle is \( 30^\circ \).
2. Recall that instantaneous voltage is given by
v = V_p \sin(\theta)
3. Substitute the known values into the formula:
v = -300 \sin(30^\circ)
4. Solve for sine of \( 30^\circ \) (which is \( 0.5 \)):
v = -300 \times 0.5
5. Calculate the result:
v = -150\,V
6. Answer is:
-150\,V