A 25 W, 220 V bulb and a 100 W, 220 V bulb are joined in series and connected to mains which bulb will glow brighter

Explanation

When two bulbs are connected in series, the same current flows through both bulbs. The brightness of a bulb is determined by the power dissipated in it, which can be calculated using the formula P = I²R, where I is the current through the bulb, and R is the resistance of the bulb.The resistance of the 25 W bulb is higher than that of the 100 W bulb, as calculated using R = V²/P. Therefore, the 25 W bulb, with its higher resistance, will dissipate more power than the 100 W bulb for the same current and will glow brighter.Option A is correct because the 25 W bulb has a higher resistance, resulting in higher power dissipation and brightness. Option B is incorrect because the 100 W bulb has lower resistance and dissipates less power. Option C is incorrect because the description of the bulbs' power ratings is not accurate. Option D is incorrect because both bulbs will glow, but the 25 W bulb will glow brighter.