# Phasor Diagram with AC circuits

Suppose you take a 2*10^2 resistor and a 0.40 inductor and make a series circuit with a voltage source that has voltage amplitude 30 and an angular frequency of 2.5×10^2 .

**Part F (The part that I need help on):

Construct the phasor diagram.

Draw the voltage and phasors with their tails at the origin of the coordinate system. The length of the voltage phasors is given in volts; the current phasor is not drawn to scale. The orientation and length of your phasors will be graded. Previously found in other parts:

Impedence (Z) = 224 ?

Current (I) = 0.134 A

Voltage across the resistor (VR) = 27 V

Voltage across the inductor (VL) = 13 V

Phase angle with respect to the current (?) = 27 degrees

The source voltage leads the current

**Also, I don't know if this is fully important but the length of the source voltage vector (V) in the diagram is 30 (no units) and its angle is 48 degrees wrt x-axis. The vector for the current (I) is at angle of 21 degrees wrt x-axis and its length is not given.

I need the length and the angle of both VL and VR

• Would Electrical Engineering be a better home for this question? – Qmechanic Apr 6 '14 at 23:22
• Please show us what you have done to try to solve this yourself. Also, please fix the values like "2.0x102" and add units to resistance and inductance values. – Joe Hass Apr 6 '14 at 23:32
• Units of ohms and units of henries are needed. Without units this is unsolvable. Also why have you specified resistance as 2.0 x 102.what on earth does that mean? 204 ohms? – Andy aka Apr 6 '14 at 23:35

$$\underline{V} = \underline{V}_R + \underline{V}_L = R~\underline{I} + j \omega L ~ \underline{I}$$