why do I add 90degrees to this power loss factor formula with the following curr

Question

why do I add 90degrees to this power loss factor formula with the following current and volatge.

The 90degrees is circled

Thank you.

Question Find the average power loss and power factor for each of the circuits whose input current and voltage are as follows c. u= 50 sin(cult + 80°) 1 = 3 cos(Wt-20°) Step 8 of 13 Given v = 50 sin (at +80°) 1-3 cos (at-20°) = 3s1n (at-20( 90°) Comment(0) Step 9 of 13 By substituting the values of pr", lm, a, formulae, we get 1n power loss and power factor 722 50) (3) 2cos(80°-(90-20*) 2 cos(800-(90-20) = 75cos (100) P=73.86 W

Explanation / Answer

It is basic trignometry rule

Sin(90 + A) = Cos A

So given

i = 3*cos(wt - 20)

= 3*sin(90 + (wt - 20))

Here A = wt - 20

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.