Two bulbs A & B rated [200V, 50W] and [200V, 100W] are connected in series. Which will glow brighter?
Since in series, the flow of current is constant. We need to compare power with ‘R’.
P = V × I
⇒ P = V2R
RA = 220250 = 800 Ω
RB = 2202100 = 400 Ω
Since, current is constant in P = i2 R. More the resistance more will be the power and thus, the bulb glows more brightly.
Hence, Bulb A glows more.