Question

State Ohm’s law. Write the necessary conditions for its validity. How is this law

verified experimentally? What will be the nature of graph between potential

difference and current for a conductor? Name the physical quantity that can be

obtained from this graph.​

Answer 1

Explanation:

Ohm’s law : When the physical conditions such as temperature etc. remain same, the current flowing through the conductor is directly proportional to the potential difference applied across the ends of the conductor, i.e.,

I∝V or V∝I

IV = constant

V=IR

where R is constant of proportionality and is called resistance of the wire.

Necessary condition for validity of Ohm's Law is that physical condition such as temperature of the conductor remains same.

"Procedure"

V-I graph is a straight line passing through the origin of the graph as shown.

Conclusion : Straight line nature of graph shows that the current is proportional to the potential difference. Hence, Ohm’s law verified. The slope of V-I graph gives the value of resistance of the conductor at the given temperature.

Answer 2

Explanation:

Ohm's law states that at a constant temperature, current 'I' through a conductor between two points is directly proportional to the potential difference or voltage 'V', across the two points. That is, V = IR. The necessary condition is that the temperature ahould be constant. The nature of the graph is a straight line.25-Feb-2018