Module 4 Flashcards
Kirchhoff first law
Sum of currents entering a junction is equal to the sun of the currents leaving a junction
Emf
Energy gained per unit charge by charges passing through a supply
Potential difference
Energy gained per unit charge by charges passing through a component
Ohms law
The current through a conductor is proportional to the potential difference across it
Resistance is proportional to:
- material
- length of wire
- cross sectional area
- temperature
A kilowatt hour
1000 watts for 3600 seconds, 3.6 million joules
Kirchoffs second law
Sum of the emf is equal to the sum of the products of the current and resistance
For a series circuit
- the current has the same value at any point
- emf = sum of pd across resistors
- resistance = sum of individual resistors
For a parallel circuit
- components in each branch share same voltage as the cell
- total current = sum of branch currents
- 1/total resistance = 1/ sum of the individual resistors
Terminal pd
The potential difference across a cell
Intensity
The power transmitted per unit area
During refraction
A wave will change its speed and may change direction
Interference
The addition of two or more waves that results in a new pattern
The principle of superposition
When two or more waves of the same type meet, the resultant wave can be found by the adding the displacements of the individual waves
A quantum
A small discrete unit of energy
