4.2.1.2

Electrical charge and current


4.2.1.2 Electrical charge and current

Content

  • For electrical charge to flow through a closed circuit the circuit must include a source of potential difference.

Electric current is a flow of electrical charge. The size of the electric current is the rate of flow of electrical charge. Charge flow, current and time are linked by the equation:

charge flow = current × time

Q =It

charge flow, Q, in coulombs, C

current, I, in amperes, A (amp is acceptable for ampere)

time, t, in seconds, s

A current has the same value at any point in a single closed loop.

MS 3b Change the subject of an equation

MS 3c Substitute numerical values into algebraic equations using appropriate units for physical quantities

Resources

Charge Foundation

Charge Foundation answers

Charge Higher

Charge higher answers

Videos

gAgTtZHW5tuemtEy.mp4

Static hair

videoplayback.mp4

LIGHTENING strike

TraVOLTa.mp4

John Travolta

My Movie.mp4

Static electricity

Practicals

Practical

Demo :

  • Balloon to blow up to explain static electricity - show it sticking to the wall
  • Use the tesla coil to show a "field" lighing up neons.
  • Vandaar graaf
  • Bubbles
  • 2x Foil with leads (croc clips)

Practical:

11 x collection of cloth and plastic rulers

11 x coke cans for racing.


Risk

Risk:

  • Warn students of posibility of a small shock