A wire is joined to a 9 V battery, and the current is 0.25 A.
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
A wire is joined to a battery, and the current is .
- Find the resistance of the wire.
- The battery is changed for one of . What is the current?
- The wire is changed for one of , on the battery. What is the current?
Need a reminder? The key ideaShow
Ohm's law: at a steady temperature, . So and , with in ohms (). The V-I graph of such a conductor is a straight line through the origin; its slope is .
The worked solution
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. (a) .
Step 2. (b) .
Step 3. (c) .
Answer: (a) . (b) . (c) .
Check. More push, or less resistance, gives more current.
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