Question

An electric bulb draws $1.2$ $A$ current at $6.0V$. The resistance of filament of bulb will be

• A. $5\Omega$
• B. $7.2\Omega$
• C. $6\Omega$
• D. $10\Omega$

Answer 1

The correct option is A $5\Omega$

Ohm's law states that the current through a conductor between two points is directly proportional to the potential difference across the two points. Introducing the constant of proportionality, the resistance, one arrives at the usual mathematical equation that describes this relationship, I = V/R.

Rewriting this relation we arrive at $R=\frac{V}{I}=\frac{6V}{1.2A}=5ohms$.

Hence the resistance of the filament of the bulb is 5 ohms.