Question

Which has higher resistance- a 50w bulb or a 2.5w bulb and how many times?

Answer 1

A 2.5W bulb has higher resistance.

Answer 2

[OPEN BRAINLY WEBSITE TO VIEW THE ANSWER PROPERLY] Lets learn how to interpret power rating. Electric appliances are generally assigned a pair of values, power and voltage to specify certain information.First of all, the voltage is the maximum recommended value you should apply across that appliance. Apply, more voltage across it (or practically even more voltage), and your appliance may be damaged due to heating effect of current. Secondly, the power specified is the amount of heat generated per unit time at $\textbf{that}$ particular specified voltage.If you know the power generated across a resistor at a given voltage, you can apply the formula, $P=\frac{V^2}{R}$ or $R=\frac{V^2}{P}$ assuming both bulbs are rated $220 V$ which is generally the case.
$50>2.5\\\Rightarrow \frac{(220)^2}{50}<\frac{(220)^2}{2.5}\\\Rightarrow R_{50}<R_{2.5}$