Try it on paper first. A hint, the key idea and the worked solution are here when you need them.
A and a bulb, both for , are joined in series to a supply. Take their resistances as fixed. Find the current and the power of each. Which is brighter?
Joule's law: . Power , in watts. A fuse, in the live wire, melts when the current is too large.
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Step 1. Resistances. and .
Step 2. Current. .
Step 3. Powers. and .
Answer: ; and . The bulb is brighter.
Why? In series the current is the same, so the larger resistance takes the larger power.
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