Question

Out of two bulbs are rated $50W,100W$. Which one will glow brighter if they are connected in series?

• A. 50 W
• B. 100 W
• C. Both have same brightness
• D. Insufficient Information.

Answer 1

The correct option is A 50 W

We know that the power of a bulb is inversely proportional to the resistance, so the 50W bulb has a higher resistance. Both bulbs are connected in series i.e. same current will flow through both the bulbs.

We also know that $Power=I^{2}R$, therefore the bulb having higher R will be brighter.