Would a dimmer be hooked in series or in parallel with the to be controlled? why?

Question

plz help me with some physics hw

Answer 1

Series.

A dimmer in parallel would work by sucking off the current. It would have high resistance for bright light (sending all the current to the bulb). It would have low resistance to dim the light, though, which would waste a tremendous amount of energy when you turn the thing off. If you had an ideal fixed voltage source (which you never do really), the dimmer in parallel would not work at all. No matter how much current you suck off, the voltage source will keep supplying the needed voltage to keep the light bright.

By putting it in series, you can dim or turn off the light without having to have a huge diversion of current and waste.

Answer 2

Usually in series. A parallel arrangement would work also if all that you wanted to was to dim the light, but you wouldn't be able to cut the light off.

Draw a circuit diagram, and you should be able to see why.