Parallel circuit with internal resistance

[dbag123]

Homework Statement

Calculate current through the source

Relevant Equations

P=UI, U=RI

4 resistors R1= 10 Ohm R2= 7 Ohm R3= 6 Ohm R4 = 18 Ohm, internal resistance of source is 0,5 Ohm and supply voltage is 27V

Total resistance in parallel resistors 1/R = 0.465 taking the inverse of that i get 2,15 Ohm. Add to that the internal 0,5 and the total comes out to 2,65 Ohm.

Total current would then be U/R --> 10,2A rounded up. If it is true that in a parallel circuit the voltage stays the same, than it stands to reason that the sum of the currents should add up to 10,2 but they dont. i get a total current of 12,577 just for the 4 resistors. What is happening here?

 

[phinds]

What is happening here?

WHERE? Show a circuit diagram.

 

[dbag123]

 

[mjc123]

If the supply voltage is 27V, the internal resistance is 0.5Ω and the resistance of the parallel set is 2.15Ω, what is the voltage drop across the parallel resistors? (hint: it is not 27V)

 

[dbag123]

21,93V

 

[mjc123]

And if you have a voltage drop of 21.93V across the 4 parallel resistors, what is the total current through them?

 

[dbag123]

10,2A