A 25 W and a 100 W bulb are joined in series and connected to the mains. Which bulb will glow brighter ?

Question

A 25 W and a 100 W bulb are joined in series and connected to the mains. Which bulb will glow brighter ? (A)  (B)  (C)  (D)

Tardigrade Admin · Accepted Answer

In series current is same. Therefore, from the relation P = i2R, a bulb having more resistance consumes more power or glows brighter. 25W bulb has more resistance ( R = (V2/P) ) compared to 100 W bulb. Hence, it will glow brighter.

Q. A 25 W and a 100 W bulb are joined in series and connected to the mains. Which bulb will glow brighter ?

In series current is same. Therefore, from the relation $P = i^{2}$ R, a bulb having more resistance consumes more power or glows brighter. 25W bulb has more resistance $(R = \frac{V ^{2}}{P})$ compared to 100 W bulb. Hence, it will glow brighter.

Q. A 25 W and a 100 W bulb are joined in series and connected to the mains. Which bulb will glow brighter ?

In series current is same. Therefore, from the relation P=i2R, a bulb having more resistance consumes more power or glows brighter. 25W bulb has more resistance (R=PV2​) compared to 100 W bulb. Hence, it will glow brighter.

In series current is same. Therefore, from the relation $P = i^{2}$ R, a bulb having more resistance consumes more power or glows brighter. 25W bulb has more resistance $(R = \frac{V ^{2}}{P})$ compared to 100 W bulb. Hence, it will glow brighter.