The Loop Rule
Circuits, conductors — and why the gap kills the glow
What this lesson covers
Why it matters
A cell, a bulb, two wires — and nothing happens until the very last joint clicks shut. Electricity is fussy: it goes all the way around, or it doesn't go at all.
Predict first
A bulb glows only when the circuit is…
Current needs a full round trip: cell → wire → bulb → wire → back to the cell. One gap anywhere, and everything stops.
- a complete, unbroken loop — correct
- connected to the cell at one point
- made of long wires
What you do
Close the switch and light the bulb — then cut the wire on the far side and watch the whole loop give up.
Check yourself
Electric wires are covered in plastic because plastic…
Copper carries; plastic guards. Every cable is a conductor wearing an insulator.
In your home, bulbs and fans are connected in…
A torch is a SERIES loop (one path). A house is PARALLEL — that''s why switching off the fan doesn''t kill the lights.
Which is a safety rule for electricity?
Wet skin conducts — water turns you into part of the circuit.
- is an insulator — it keeps the current in and your fingers safe — correct
- is colourful
- makes current flow faster
- parallel — each has its own path and its own switch — correct
- series — one loop through everything
- no circuit at all
- never touch switches or sockets with wet hands — correct
- use the thinnest wire available
- poke sockets to test them