Choose the incorrect statement from the following.

The correct answer is option 3) i.e. Ohm's law is universally applicable for all conducting elements.

CONCEPT:

• Ohm’s law: It gives the relation between current, voltage, and resistance in a circuit.
  • Ohm’s law states that the current through a conductor between two points is directly proportional to the voltage across the two points.

i.e. V ∝ I

Therefore, V = IR

Where R is the resistance.

• This law is valid only for a conductor at the same physical and temperature conditions. 
• For a conductor at a constant temperature, the plot of V-I graph will be a straight line through the origin.
• The slope of the V-I graph gives the value of resistance.

EXPLANATION:

• The slope of voltage versus current graph = V/I = R.
• Therefore, the slope of the voltage vs current graph is resistance.
• The most fundamental law in electricity is Ohm's law as it governs the relationship between the basic parameters of electricity - current, voltage, and resistance.
• A semiconductor is a conducting material but does not obey Ohm's law. Hence, not all conducting materials obey Ohm's law.