R and I of DC circuit

In summary, the net resistance of the circuit connected to the battery is 2.9kΩ. The current flowing into junction c and branch ca from the battery is V=ir.
  • #1
scrubber
20
0

Homework Statement


http://postimg.org/image/8oweasluj/
Each rectangle in the figures represents a resistor with resistance=2.9kΩ.

a) What is the net resistance of the circuit of Fig 1 connected to the battery? Each resistance has R=2.9 kΩ.

b) What is the current flowing into the junction c and the branch of ca from the battery?

c) If we replace the branch of bc with a 12V battery as Fig 2 shows and Vb>Vc, what is the current flowing into the branch of CA?

The Attempt at a Solution



a) Is the circuit in Fig 1 equal to that of Fig 3 as below?
http://postimg.org/image/t5cwrllzt/

Thank you.
 

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  • #2
Yes, you can take it and solve it
 
  • #3
Sumanth said:
Yes, you can take it and solve it

Thank you so much! :D
I know part a then, just apply the parallel and series equations.

But for part b, does it mean that first I have to calculate the total current =It,
then apply Ic=It*(Rt-Rc/Rt), where Rt represents the total resistance?
 
  • #4
No, just apply ohm's law
 
  • #5
V=ir. R means effective resistance
"i"means total current through the cell.
And then divide current into the branches of circuit in corresponding ratios.
 
  • #6
Sumanth said:
V=ir. R means effective resistance
"i"means total current through the cell.
And then divide current into the branches of circuit in corresponding ratios.

I see! I understand now :D Thank you so much!
How about part c then?
Should I use Kirchhoff's Rule? But can Kirchhoff's Rule be applied if there's more than two loops?
 
  • #7
And in part b, the current flowing into junction c and branch ca would be the same then?
(Since the ratio of resistance are the same?)
 
  • #8
For part b, can I rather use V=IR to find out the current through branches directly after finding out the total current?
 
  • #9
Kirchoff law can be applied separately to any number of loops and solve then separately to find currents
 

What is R and I of DC circuit?

R and I refer to resistance and current, respectively, in a DC circuit. Resistance is the measure of an object's opposition to the flow of electric current, while current is the flow of electric charge through a conductor.

How are R and I related in a DC circuit?

Ohm's law states that in a DC circuit, the current is directly proportional to the voltage and inversely proportional to the resistance. This means that as the resistance increases, the current decreases, and vice versa.

What is the unit of measurement for R and I in a DC circuit?

The unit of measurement for resistance is ohms (Ω), while the unit for current is amperes (A). These units are named after the scientists who discovered them.

How do R and I affect the overall performance of a DC circuit?

In a DC circuit, the amount of resistance and current can determine the voltage and power of the circuit. High resistance can lead to a decrease in current and voltage, while high current can increase the voltage and power.

What are some common applications of R and I in DC circuits?

R and I are important in many electronic devices, such as computers, televisions, and smartphones. They are also used in power distribution systems to regulate the flow of electricity and prevent damage to equipment.

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