Electric Circuits, Kirchhoff's Rules

In summary: Kirchhoff's laws state that the current through node A is equal to the magnitude of the voltage across it. The current through node A in this case is 16 V. From node A, the current flows through node B and then into node C. The voltage across node C is 11 V.
  • #1
yayirunin2car
12
0
The question: Suppose point A is grounded (V = 0) in Figure 21-36, in which script e = 16 V and R = 11 . Find the potential at points B and C.

Here is the diagram:
http://www.webassign.net/walker/21-35alt.gif

I'm pretty sure that I have to use Kirchhoff's rules in order to solve this problem, but I'm afraid that I've been reading them over and over and don't completely understand them. Especially with this 'grounded' stuff. Does that mean that I just ignore that part of the circuit, where 6.2 and 11 ohm are? I guess I need a little bit of guidance in how to start solving this.
 
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  • #2
yayirunin2car said:
The question: Suppose point A is grounded (V = 0) in Figure 21-36, in which script e = 16 V and R = 11 . Find the potential at points B and C.

Here is the diagram:
http://www.webassign.net/walker/21-35alt.gif

I'm pretty sure that I have to use Kirchhoff's rules in order to solve this problem, but I'm afraid that I've been reading them over and over and don't completely understand them. Especially with this 'grounded' stuff. Does that mean that I just ignore that part of the circuit, where 6.2 and 11 ohm are? I guess I need a little bit of guidance in how to start solving this.

You can develop the equivalent resistance for the circuit to make it a bit easier. Then you have the current flowing through nodes A, B, and C. The voltage potentials are then determined easily.
 
  • #3
Thank you very much! I got the correct answers - only I had to change point C into having a negative voltage. I don't exactly understand why it's negative though.
 
  • #4
yayirunin2car said:
Thank you very much! I got the correct answers - only I had to change point C into having a negative voltage. I don't exactly understand why it's negative though.

The initial condition of the problem is that node A is held at ground.
 

FAQ: Electric Circuits, Kirchhoff's Rules

What are Kirchhoff's Rules?

Kirchhoff's Rules, also known as Kirchhoff's Laws, are two fundamental principles in electrical circuit analysis. These rules are used to determine the voltage and current distribution in a circuit.

What is Kirchhoff's first rule?

Kirchhoff's first rule, also known as the Kirchhoff's Current Law (KCL), states that the sum of all currents entering a node in a circuit must be equal to the sum of all currents leaving that node. This rule is based on the principle of conservation of charge.

What is Kirchhoff's second rule?

Kirchhoff's second rule, also known as the Kirchhoff's Voltage Law (KVL), states that the sum of all voltages around a closed loop in a circuit must be equal to zero. This rule is based on the principle of conservation of energy.

How are Kirchhoff's Rules used in circuit analysis?

Kirchhoff's Rules are used to solve for unknown voltages and currents in a circuit. By applying KCL and KVL to different parts of a circuit, we can create a system of equations that can be solved to determine the values of these unknown variables.

Are Kirchhoff's Rules applicable to all types of circuits?

Yes, Kirchhoff's Rules are applicable to all types of circuits, including DC and AC circuits. They can also be applied to complex circuits with multiple voltage sources and resistors.

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