A string of 20 identical lamps is joined in series to a 220 V supply…
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
A string of identical lamps is joined in series to a supply.
- What potential difference does each lamp get?
- One lamp's filament touches itself, so that lamp is shorted out (it has no resistance now). What does each of the other lamps get? Are they brighter or dimmer?
Need a reminder? The key ideaShow
In series, the same current flows through every resistor, the potential differences add up, and
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) each.
Step 2. (b) The shorted lamp takes no share, so lamps share the supply: each.
Step 3. Brightness. More voltage across each, and more current, so the other lamps glow brighter, and may wear out sooner.
Answer: (a) . (b) about each; brighter.
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