Question

A torch bulb when cold had a resistance of 2.5ohm it draws a current 0.45mA when connected to a 6V battery and glows brightly calculate the resistance of the bulb when glowing and explain the reason for the difference in resistance

Answer 1

Answer:

Explanation:

Given,

R1= 2.5Ω

l=0.45mA = 0.45x 10^-3A

v=6V

R2=v/l= 6/0.45x10^-3 = 13333.33Ω

R2-R1=13330.83

The difference is because when the temperature increases as the current flows through it , the resistance also increases.

    R∝T