Question

State Ohm's law.

Answer 1

Ohm's law:

1. The charge per unit time flowing through a circuit is known as current.
2. The measure of opposition offered to the current in a circuit is known as resistance.
3. The amount of work done in moving a unit charge from one point to another in an electric field is known as electric potential.
4. Ohm's law states that “The voltage across a conductor is directly proportional to the current through it provided that all physical conditions and temperature remain same.” That is, $V\propto I$, where $V$ is potential and $I$ is current.
5. The above statement can be further written as $V=IR$, where $R$, the proportionality constant is resistance. The value of this constant depends upon nature, length, area of cross-section, and temperature.
6. Ohm's law is followed only if the temperature remains constant. When the temperature increases, Ohm's law is violated. For example, the temperature of the light bulb filament increases due to current, so Ohm's law is not followed in this case.

Hence, Ohm's law states that “The voltage across a conductor is directly proportional to the current through it provided that all physical conditions and temperature remain same.”