# inductance from graph

Discussion in 'General Electronics Chat' started by blpanther, Feb 2, 2016.

1. ### blpanther Thread Starter New Member

Nov 23, 2015
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0
Hi, Need help with some questions:
I need to determine the inductance from the gradient of graph (graph is showing frequency changing from 500-2500Hz vs inductor voltage) circuit current is kept same by increasing signal generator voltage... The gradient of the graph is vertical length divided by horizontal length but if I use that it doesn't even come close to the value of inductance (which is 100mH).

2. ### Alec_t AAC Fanatic!

Sep 17, 2013
5,979
1,138
We're not psychic .
If frequency is along one graph axis, what is along the other axis?
Apart from an inductor, what else is in your circuit? A schematic of your circuit would help.

3. ### blpanther Thread Starter New Member

Nov 23, 2015
5
0
on the other axis we have inductor voltage. in the circuit there is only a resistor and this inductor (in series) plus a signal generator.

4. ### MrChips Moderator

Oct 2, 2009
12,648
3,458
Units, units, units!

$Reactance = \omega L$

Reactance in ohm.

$\omega = 2\pi f$ in radian/s

$L$ in Henry.

$L = \frac{Reactance}{2\pi f}$

The denominator $f$ is in Hz multiplied by $2\pi$.

The numerator is in ohm.

Last edited: Feb 3, 2016
5. ### blpanther Thread Starter New Member

Nov 23, 2015
5
0
so on the graph I have following points
(0,0) and for example (2500,950) - frequency and voltage respectively.
If I divide 950/2500 I get 0.38 as graph gradient. How does that relate to inductance (which is 100uH) ?

May 20, 2015
673
194
See:

7. ### Alec_t AAC Fanatic!

Sep 17, 2013
5,979
1,138
Is this 'homework help'? If so, show us your calculations so far.