Using complex numbers to solve for a current in this circuit

• GJ1
In summary: Precise.In summary, the OP is trying to solve an equation for current in a circuit, but he can't seem to get it right. He started with a complex number and simplified it down to 5. Then he plugged it back in to the original equation and got the correct answer.
GJ1 said:
Can you just explain how you get 50/2+j from 150/(4+j)+2
He doesn't. He gets 50/(2+j) from 150/( (4+j3)+2 ).

This is not just a picky complaint. In these days of computers and calculators, they will always give you the wrong answer if the parenthesis are wrong.

Last edited:
scottdave
Just got it. Thanks for explaining it with your example. Greatly appreciated!!!!!

FactChecker and berkeman
PeroK said:
And yet:
$$\bigg [\frac{50}{(4 + j3)(50) + 100} \bigg ] \times 150 = \frac{150}{(4 + j3) + 2}= \frac{50}{2+ j} = \frac{(50)(2 - j)}{5} = 20 - j10$$
I stand corrected.

FactChecker said:
He doesn't. He gets 50/(2+j) from 150/( (4+j3)+2 ).

This is not just a picky complaint. In these days of computers and calculators, they will always give you the wrong answer if the parenthesis are wrong.
Understood

FactChecker and berkeman
Mark44 said:
I stand corrected.
And now the OP has what he wanted. A solution on a plate!

PeroK said:
And now the OP has what he wanted. A solution on a plate!
Right. But it won't go very far unless the OP has learned from this thread. Still, we should be careful to not give in to frustration and just give the answer.

scottdave
FactChecker said:
Right. But it won't go very far unless the OP has learned from this thread.
We could give them a similar complex number manipulation question to test their understanding. Any volunteers?

FactChecker
GJ1 said:
It's (50/(4+j3)(50)
Those parentheses do not match up. You are missing a "closing paren" somewhere. I'm having a little trouble guessing what the 50 over (4+j3) represents. What about the second 50? Some units would be nice.

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