Question

an RL circuit is connected to a 81V (f=60Hz) AC source. if the resistor is 40 ohms and inductor is 216 mH. what angle does each of these phasors (resistor, inductor and total) make with the positive real axis??

Answer 1

• In case of resistor, the voltage and the current are in same phase or we can say that the phase angle difference between voltage and current is zero.
• In inductor, the voltage and the current are not in phase. The voltage leads that of current by 90°.

V= 81.0
f = 60 Hz
R= 40 Ohms
L= 216 mH

So far i was able to get
XL = ω * L
ω = 2*pi*f

XL = 2*pi*f * L
XL = 2*3.14 *60 * 216 * 10^-3
XL = 81.388

tan(Ø) = XL/R
Ø = tan^-1(XL/R)
Ø = tan^-1(81.388/40)
Ø  = 63.83^o



Angle Resistor makes with +ve real axis = 0
Angle Inductor makes with +ve real axis = 90
Angle Total makes with +ve real axis, Ø = 63.83^o