Question

state and proof ohms law

Answer 1

Statement of Ohm's Law:
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 propto I

or frac{V}{I} = constant = R

or V = IR

Thus, the ratio V : I is a constant. This constant is called as the resistance (R) of the conductor.

Graph:

After performing experiment for different readings of V & I and recording the observations, if we plot current on the x-axis of a graph and voltage on the y-axis of the graph, we will get a straight-line. The gradient of the straight-line graph is related to the resistance (R) of the conductor.



Related Theory:
Resistance:
Resistance is the property of a component which restricts the flow of electric current. Energy is used up as the voltage across the component drives the current through it and this energy appears as heat in the component.
Resistance is measured in ohms, the symbol for ohm is an omega(Ω).
Resistors connected in Series:
When resistors are connected in series their combined resistance is equal to sum of thier the individual resistances. For example if resistors R1 and R2 are connected in series their combined resistance, R, is given by:

R = R1+R2

Resistors connected in Parallel:
When resistors are connected in parallel their combined resistance is less than any of the individual resistances. Equation for the combined resistance R of 2 resistors R1 and R2 connected in parallel is given by:

frac{1}{R}=frac{1}{R1}+frac{1}{R2} OR R =frac{1}{frac{1}{R1}+frac{1}{R2}}

Answer 2

According to Ohms law, the current flowing in a conductor is directly proportional to the potential difference across its ends provided the physical conditions and the temperature of conductor remain constant.