Ohm's law

OHM’S LAW : OHM’S LAW Presentation by BYJA B

Ohm’s Law : Ohm’s Law Current flows in a conductor when a potential difference is maintained across its ends. In 1826, a German scientist George Simon Ohm stated this law. George Simon Ohm

Slide 3 : According to Ohm’s law, “the current flowing in a conductor is directly proportional to the potential difference across its ends provided the physical conditions and temperature of conductor remains constant”. that is , Ia V where I = current flowing V= potential difference across the ends of the conductor If ‘V’ across the conductor is doubled, ‘I’ in it also get doubled.

Limitations of Ohm’s Law : Limitations of Ohm’s Law Ohm’s law is obeyed only when the temperature of the conductor remains constant. Explanation I a V or V/I = constant For metallic conductor, this ratio is constant for all values of V and I. Put the constant equal to R, the resistance of conductor; eqn becomes V = IR Click here

I –V graph for a metallic conductor : I –V graph for a metallic conductor 0 V I x x x In the above graph, we get a straight line passing through the origin, since the relationship between V and I is linear.

Slide 6 : ?I ?V V 0 I X Y R= ?V/ ?I = slope of V vs. I graph V – I graph

Slide 7 : If I = 1, then V = R Thus resistance of a conductor is numerically equal to the potential difference across its ends when unit current flows through it. Experimental Verification of Ohm’s Law + - - + -