Calculate Inductor Maximum Energy: 240V, 50Hz, 4A & Negligible Resistance

Click For Summary

Discussion Overview

The discussion revolves around calculating the inductance and maximum stored energy in an inductor when a 240V, 50Hz voltage is applied, resulting in a 4A current, assuming negligible resistance. The context includes homework-related calculations involving AC circuits.

Discussion Character

  • Homework-related

Main Points Raised

  • One participant calculates the inductance as 0.191H and the energy stored as 1.528J using the formula E=0.5Li^2, but expresses confusion over a discrepancy with a provided answer of 3.06J.
  • Another participant notes that the voltage and current values are likely RMS values.
  • A later reply emphasizes the need to use peak current (I pk) for energy calculations, leading to a recalculation of energy as 3.06J.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the correct method for calculating the maximum stored energy, as there are differing approaches regarding the use of RMS versus peak current.

Contextual Notes

The discussion highlights potential limitations in understanding the distinction between RMS and peak values in AC circuits, which affects the energy calculation.

jendrix
Messages
120
Reaction score
4

Homework Statement



Assuming steady-state sinusoidal ac.A voltage of 240V at 50Hz applied to an inductor yields a current of 4A.Assume negligible resistance.Find inductance, max stored energy.



Homework Equations



E=0.5Li^2

X=2*pi*f*L


The Attempt at a Solution



V/I=X Which I found to be 60

L=60/2*pi*f
L=0.191H

E=0.5*0.191*4^2
E=1.528J

However the answer given is 3.06J , which has left me confused.

Thanks
 
Physics news on Phys.org
The given voltage and current values are no doubt RMS values...
 
  • Like
Likes   Reactions: 1 person
jendrix said:
assuming steady-state sinusoidal ac.a voltage of 240v at 50hz applied to an inductor yields a current of 4A. Assume negligible resistance. Find inductance, max stored energy.
[/color][/color]
Maximum energy is stored when maximum current flows through it.
 
  • Like
Likes   Reactions: 1 person
Of course, I need to use I pk,

so E=0.5*0.191*(4*2^1/2)^2=3.06J

Thanks :)
 

Similar threads

  • · Replies 18 ·
Replies
18
Views
5K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 7 ·
Replies
7
Views
4K
  • · Replies 17 ·
Replies
17
Views
6K
  • · Replies 2 ·
Replies
2
Views
9K
Replies
34
Views
7K
Replies
16
Views
5K
  • · Replies 9 ·
Replies
9
Views
5K
  • · Replies 3 ·
Replies
3
Views
8K