How to Solve an Electric Circuit Like This?

[askor]

Can someone please tell me to find R of this electric circuit?
Please tell me the step-by-step.
I have many problems of electric circuit like this.
If you show me one, perhaps I can solve the rest of them.

 

[davenn]

Can someone please tell me to find R of this electric circuit?
Please tell me the step-by-step.

This looks like homework, but even if it isnt, we will not just give you the answers here at PF
we expect you to make some effort to trying to solve problems yourself.

So with that said, where do you think would be a good place to start working it out ?

 

[askor]

This looks like homework, but even if it isnt, we will not just give you the answers here at PF
we expect you to make some effort to trying to solve problems yourself.

So with that said, where do you think would be a good place to start working it out ?

OK, here is my attempt.

R1 = 6 Ω
R2 = 8 Ω
R3 = 10 Ω
R4 = 15 Ω

R3 and R4 are parallel and form a R5, so

$\frac{1}{R5} = \frac{1}{R3} + \frac{1}{R4}$
$\frac{1}{R5} = \frac{1}{10} + \frac{1}{15}$
$\frac{1}{R5} = \frac{1.5 + 1}{15}$
$\frac{1}{R5} = \frac{2.5}{15}$
$R5 = \frac{15}{2.5}$
$R5 = 6 Ω$

What next?

 

[sophiecentaur]

What next?

Have you come across Kirchoff's Laws?

 

[anorlunda]

Moved from a technical forum, no template.

 

[sophiecentaur]

What next?

What's needed in a problem like this is a systematic approach.You have reduced the circuit already by converting those two resistors to just one. Then you use Kirchoff's laws to produce some simultaneous equations for the currents and voltages around a circuit. Looks a pain but this problem is not too hard. There is no point in my explaining Kirchoff if you know it already.