What is the Internal Resistance of a Practical Current Source?

Click For Summary

Discussion Overview

The discussion revolves around the internal resistance of a practical current source, specifically in the context of a problem involving measurements taken with an ammeter and additional resistances. The scope includes theoretical considerations and practical applications related to electrical circuits.

Discussion Character

  • Homework-related
  • Technical explanation

Main Points Raised

  • The problem presents a scenario where the current at the terminals of a current source is measured with an ammeter, and participants are tasked with finding the internal current and resistance of the source.
  • Some participants suggest that for a practical current source, the internal resistance should be represented as a resistor in parallel with the ideal current source.
  • A participant notes that the thread may have been misplaced as a homework thread and expresses doubt that the original poster will engage with the responses.

Areas of Agreement / Disagreement

There is no consensus on the resolution of the problem, and the discussion appears to be unresolved with participants expressing uncertainty about the original poster's engagement.

Contextual Notes

The discussion lacks detailed assumptions regarding the circuit configuration and the implications of the measurements taken. There are also unresolved mathematical steps related to the calculations of the internal current and resistance.

Salman
Messages
5
Reaction score
0
PROBLEM:the current at the terminals of a certain current source is measured with an ammeter having an internal resistance [tex]R_i=10 ohms[/tex] and is found to be [tex]11.988 mA[/tex] ;adding a [tex]1.2 kilo -ohms[/tex] resistance between the source terminals causes the ammeter reading to drop to [tex]11.889 mA[/tex].Find [tex]i_s[/tex] and [tex]R_s[/tex]

NOTE:[tex]i_s[/tex] and [tex]R_s[/tex] constitute a practical current source.i.e [tex]R_s[/tex] is the internalresistance of the source [tex]i_s[/tex]
 
Physics news on Phys.org
For a practical current source, the internal resistance should be shown as a resistor parallel to the "ideal" current source.
 
Misplaced homework thread closed for Moderation...
 
Oh duh, this is a way old problem that got put in the Open Practice Problems forum. Dave, I don't think the OP is going to read our replies...
 
  • Like
Likes   Reactions: scottdave
Ha, I just realized what the date was on that.
 

Similar threads

Engineering Finding Internal Resistance through Circuit Analysis
  • · Replies 9 ·
Replies
9
Views
2K
Engineering Why is the voltage source high potential into node 1 at -12 V in this op amp problem?
  • · Replies 15 ·
Replies
15
Views
3K
Engineering How do I find Vth with the node voltage method?
  • · Replies 10 ·
Replies
10
Views
4K
Engineering Voltages and current in a circuit: incorrect signal?
  • · Replies 8 ·
Replies
8
Views
2K
Engineering Norton/Thevenin Equivalent circuits with a dependent voltage source
  • · Replies 9 ·
Replies
9
Views
6K
Engineering Calculating current and voltage of a rectifier circuit
  • · Replies 3 ·
Replies
3
Views
2K
Engineering Finding the Thevenin Equivalent Circuit for a Network with a Load Resistor
  • · Replies 1 ·
Replies
1
Views
2K
Connecting a number of EMF sources in a circle to form a circuit
  • · Replies 9 ·
Replies
9
Views
1K
Engineering Transistor circuit: Determine source resistance
  • · Replies 7 ·
Replies
7
Views
3K
Numerical problem about circuits
  • · Replies 2 ·
Replies
2
Views
2K