# A small bulb has a resistance of 2 ohm when it is cold. It draws 0.4 ampere current from a source of4V and then starts growing. Calculate the resistance when it is glowing

Given,

Resistance = 2 Ohm

Current = 0.4 Ampere

Voltage = 4V

According to Ohm’s law,

V = I x R

Therefore, $R=frac{V}{I}$

Substituting the values in the above equation, we get

R = 5 Ohm