Question

what is ohms law and what is resistance ​

Answer 1

Ohm's Law :

According to it the potential difference (V), across the end of two wires is directly proportional to the current (I) flowing through that wire, the provided temperature remains the same.

This law was given by Georg Simon Ohm.

According to definition :

V $\alpha$ I

If we remove the sign of $\alpha$ then there came a constant which is R (resistance).

V = IR

Resistance (R) :

From above equation it is clear that R is constant for the given metallic wire at a constant temperature.

It resist the flow of charge to the wire.

=> S.I. Unit = Ohm.

=> R = V/I

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° 1 Ohm :-

If the potential difference of 1 V (volt) is applied across the end of wire then the current through that wire is 1 A (ampere) then the resistance is said to be 1 Ohm.

1 Ohm = 1 V/ 1 A.

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Answer 2

Ohm's Law :

Ohm's law states that the current (I) passing through a conductor is directly proportional to the potential difference (V) across its ends, provided the physical conditions like temperature, density, etc. remains unchanged.

Mathematically :

Potential difference ∝ Current

or

Potential difference = Resistance × Current

or

V ∝ I

or

V = RI

Here, Resistance (R) is a constant.⠀ ⠀⠀ ⠀ ⠀⠀ ⠀

Resistance :

It is a property of conductor by virtue of which it opposes the flow of current through it. It is equal to the ratio of the potential difference applied across its ends and the current flowing through it

Mathematically :

$\sf Resistance = \dfrac{Potential \: difference}{Current}$

or

$\sf R = \dfrac{V}{I}$