# Homework Help: Argand diagram, phase difference & power

1. May 23, 2013

### eddievic

1. The problem statement, all variables and given/known data
The potential difference across a circuit is given by the complex number

V=40+j35volts

and the current is given by the complex number

I=6+j3 amps

a) sketch the appropriate phasors on an Argand diagram.
b) Find the phase difference between the phasors for voltage V and current I
c)Find the power (watt) given that

power = VxIxcos∅

3. The attempt at a solution

a) Argand diagram attached (I wonder have I maybe took this too literal as it seems too simple?)
=14.6°
c)P=VIcos∅
V=√40^2+35^2=53.151
I=√6^2+3^2=6.7082
so substituting into equation
(53.151)(6.7082)(0.9676)=345 watts

#### Attached Files:

• ###### Argand Diagram.pdf
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Last edited: May 23, 2013
2. May 25, 2013

### barryj

3. May 28, 2013

### eddievic

how so?

4. May 28, 2013

### barryj

Looks like you have V = 35 + j40 plotted. I looks OK.

5. May 28, 2013

### eddievic

Ah right thanks for there'll

6. May 28, 2013

### eddievic

Silly phone should say reply :-)