Question

3. 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

According to ohm's law the potential difference applied across the conductor is directly proportional to the current flowing through the cross - section of a conductor.

The condition for its validity are :-

• If the physical factors like temperatures and pressure remains constant.

The appliances which follows ohm's law is known as ohmic conductor.

To verified law experimentally.

Material Required :-

Voltmeter, ammeter, Rheostat.

Procedure:-

Connect Them With the D. C supply and measure the potential difference and current when the rheostat is fixed.

Now, measure the value by adjusting the rheostat.

Conclusion:-

You see that in every reading the ratio of potential difference and current remains constant.

$\huge \boxed {\dfrac{V}{I} = R (K) }$

Nature of Graph :-

The graph of potential difference and current is straight line.

The physical quantity which is obtained from this graph is Resistance.

Resistance :- It is the property of a conductor to resist the flow of electric current through it is called resistance.

• It's SI unit is Ohm.

Answer 2

Answer:

Ohm’s law states that the electric current flowing through a metallic conductor is directly proportional to the potential difference across the ends of the conductor provided the temperature remains constant.

Mathematically,

VαI

V=RI where R is the constant of proportionality called the resistance of the conductor.

The necessary condition is that the temperature ahould be constant. The nature of the graph is a straight line.The physical quantity that can be determined is the gradient of the straight-line graph which is related to the resistance (R) of the conductor.