Question

Few bulbs of same wattage are connected in series in a circuit. Will there be a difference in the brightness of these bulbs, i.e., will the bulb near to the battery glow brighter than the farther one?

Answer 1

In series circuit, the same current will flow through each bulb.
Given, power of each bulb is same.
Since, P = I²R
​Resistance (R) of each bulb will be same as P and I is same for each bulb.
We know that light of a bulb is directly proportional to the heat produced by it, due to the flow of current through it, i.e., H = I²Rt. Hence, the brightness of each bulb will be same if time period t in which the current flowing though the each bulb is taken same.