Question

State Ohm's law. Derive the equation

Answer 1

Ohm’s law states that the current (I) flowing through a conductor is directly proportional to the potential difference (V) across the ends of the conductor,provided physical conditions of the conductors such as temperature,mechanical strain etc. are kept constant.

Derivation:-

As drift velocity is given by Vd=eEt/m

But                         Electric field across the conductor of length l is

E=V/l

Thus                              Vd=e V/ml

Also,                              I=Anevd ..........1

By putting value of vd in the equation of 1,we get:-

I = Ane(eV/ml) = (Ane2/ml)V

Or                        V/I=ml/Ane2=R

Where R is a constant for a given conductor. It is known as the resistance of the conductor.

Thus, V=RI (Ohm's law)

Answer 2

Answer:

Explanation:

Ohm's Law :-

It states that , on a constant temperature , the current  I , flowing through the electric circuit , is directly proportional to the potential difference V , across its ends.

 V ∝ I

 I ∝ V

V/ I = R , constant of proportionality

R = Resistance [ opposes flow of current ]

V  = IR 

R = V/I

I = V / R