Resistance from V-I graph

[Cici2017]

Homework Statement

Is the resistance equal to V/I at any point, or is it the gradient at that point? And Why?

Homework Equations

The Attempt at a Solution

shouldn't it be the gradient? because it is change in V over change in I?

Thanks~

 

[cnh1995]

shouldn't it be the gradient? because it is change in V over change in I?

Yes, it's the gradient. But for ohmic materials (linear resistances), the gradient is same as V/I.
Can you say why?

 

[Cici2017]

Yes, it's the gradient. But for ohmic materials (linear resistances), the gradient is same as V/I.
Can you say why?

Yes =) Thanks for making it clear