An ac generator has emf Epsilon = Epsilon_m sin(omega_dt - x/4), where epsilon_m

Question

An ac generator has emf Epsilon = Epsilon_m sin(omega_dt - x/4), where epsilon_m = 31.5 V and omega_d = 318 rad/s. The current produced in a connected circuit is i(t) = I sin(omega_dt - 3 pie/4), where I = 732 mA. At what time after t = 0 does the generator emf first reach a maximum and the current first reach a maximum The circuit contains a single element other than the generator. Is it a capacitor, an inductor, or a resistor What is the value of the capacitance, inductance, or resistance, as the case may be

Explanation / Answer

a) E = Em    when    sin(wt – pi/4) = 1 =====è wt = 3pi/4

t = 3pi/4w = (3pi)/(4*318) = 0.00741 sec

b) I = I   when   wt – 3pi/4 = pi/2 =======è wt = 5pi/4

t = 5pi/4w = (5pi)/(4*318) = 0.01235 sec

c) Current peaks after the emf. (current lags voltage by pi/2)

So it is INDUCTOR

d) VL = IL*XL                 XL = wL

VL = IL(wL)=======è L = VL/(Iw) = Em/(I*w) = 31.5/(318*732*10^-3) = 0.135 H

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

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