Electricity: common misconceptions

If your child says… “Current still flows through a break.”

Ask together

Where could charge cross the gap?

What’s true

A break interrupts sustained charge flow.

If your child says… “The voltage number is the total energy.”

Ask together

Does voltage alone tell us how much charge moved?

What’s true

More charge transfers more energy at unchanged voltage.

If your child says… “Every device always obeys Ohm's law.”

Ask together

Does a warming filament keep its temperature unchanged?

What’s true

Heating can change resistance.

If your child says… “Longer wire has greater resistivity.”

Ask together

Do the top and middle wires differ in material or only in length?

What’s true

Resistivity depends on material and temperature.

If your child says… “Each resistor uses up some current.”

Ask together

Where would charge collect if less left each resistor than entered?

What’s true

In a steady, unbranched circuit, equal charge passes every point each second.

If your child says… “I add parallel resistances directly.”

Ask together

Would an extra conducting path make total current smaller at unchanged voltage?

What’s true

Combined resistance falls below either branch's resistance.

If your child says… “Double current means double heat.”

Ask together

What happens when the doubled current is squared?

What’s true

With resistance and time unchanged, doubling current gives fourfold heat.

If your child says… “Kilowatt-hours measure power.”

Ask together

What extra information does the hour add?

What’s true

A kilowatt-hour measures energy.