Question

TWO LOADS ARE CONNECTED IN PARALLEL TO AN A-C SOURCE AND TAKE CURRENTS OF 10 AND 40 AMP, RESPECTIVELY.IF THE SINUSOIDAL WAVE OF THE COMPONENT CURRENTS ARE OUT OF PHASE BY 30 ELEC DEG. CALCULATE THE RESULTANT CURRENT.

Answer 1

@CGGURUMANJUNATH @3mar @IrishBoy123

Answer 2

@inkyvoyd @sweetburger

Answer 3

ans= 48.7 A base on the book

Answer 4

@Caerus
10 cos 30 + 40 = 48.7
is my first stab at this one ..

Answer 5

I'm pretty sure that book answer is wrong. I threw the kitchen sink at this earlier and now I think @osprey has identified why there is an error :)

Think of it, even if there was a rationale for adding the current vectors this way to get the **right** answer, how do you choose between:

\(10 \cos 30 + 40\)

and

\(40 \cos 30 + 10\)

and

\(40 \sin 30 + 10\)

etc. Where is the extra asymmetry or information that pinpoints one of these approaches as the correct over the other one**s**?!

The easiest way to add these vectors is to first draw a phasor diagram.

Once you have built a phasor, here we add them as follows:


\(|I| = \sqrt { (40 \cos 30 + 10)^2 + (40 \sin 30)^2 } \approx 48.9 A\)

Answer 6

@IrishBoy123 That was my concern too ... which to "recommend" ?