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

Explanation

To determine which bulb will glow brighter when a 25W and a 100W bulb are connected in series to the mains, we can follow these steps:

### Step 1: Understand the relationship between power and resistance
The power (P) consumed by a bulb can be expressed using the formula:
\[ P = \frac{V^2}{R} \]
where \( V \) is the voltage across the bulb and \( R \) is its resistance. Rearranging this gives us the resistance in terms of power:
\[ R = \frac{V^2}{P} \]

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