Question

An alternating voltage is given by V=30sin314t.The time taken by voltage to reach -30V for first time?​

Answer 1

Answer:0.85 seconds

sine 314t =-1 at theta = 270 degrees

314 t = 270

t = 270/314= 0.85 Seconds.

Answer 2

Answer:

15 milliseconds is the time taken by alternating voltage to reach -30 V for the first time.

Explanation:

An alternating voltage is given by V=30sin(314t).

So to find the first time when voltage reaches -30V is given by substituting the value -30 in the equation,

-30= 30sin(314t)

sin(314t)=-1

$314t= \frac{3\pi }{2}$

Since, π=3.14      

$314t=\frac{3*3.14}{2}$

On solving,

t=15 milliseconds.        

Hence, the time taken by voltage to reach -30V for first time is 15 milliseconds.