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).

 

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.

 

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.

 

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.

 

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) ?

 

See:

 

Is this 'homework help'? If so, show us your calculations so far.