Electrical Principles: Going Further

Ohm's law, series and parallel, and what an appliance actually costs to run.

8 questions, free, marked as you go with a worked explanation on every one.

What this covers

A circuit carries a current of 0.5 A through a resistance of 24 ohms. What is the voltage across it?
Three identical bulbs are wired in series. One is unscrewed. What happens to the other two?
Two resistors of 6 ohms and 4 ohms are connected in series. What is the total resistance?
Which are true of a parallel circuit? Select all that apply.
A heater draws 8 A from a 120 V supply. What is its power, in watts?
That heater runs for 4 hours. At 12.5 cents per kilowatt-hour, what does it cost, in cents?
Why is a fuse or breaker fitted in series with a circuit rather than in parallel with it?
A student says a longer wire of the same material and thickness has more resistance. Is that right, and why?