HSC Physics and Chemistry

electromagnetism eq1,2,3

What is electromagnetic induction

when a changing magnetic field creates an electric current in a conductor

what is the name of the electric current produced

induced current

What needs to happen for electric current to form

potential difference

what is electromotive force(emf)

The movement of positive charges in a wire created by a changing magnetic field

back emf

a self-generated voltage created by the rotation of the motor's coils within a magnetic field(lens law)

what is lenz’s law

the direction of an induced electric current always opposes the change in magnetic field (or magnetic flux) that produced it

magnetic flux

a measure of the total magnetic field passing through a surface

Faraday’s Law of Induction

a changing magnetic field will produce a force

ways to increase current in coil

increase number of turns, increase strength of magnet and increase area of cross section

how does an electric motor transform energy

from electrical to mechanical energy

how does a generator transform energy

from mechanical to electrical energy

Do electric currents interact with eachother

no

Do electric currents interact with magnetic fields

no

do magnetic fields interact with each other

yes

what is a magnetic field induced around

conductors carrying a current and moving charges

how to change magnetic flux

change area, change angle and change field

change in flux equation

BA cos theta

flux linkage

total magnetic flux passing through a coil of wire multiplied by the number of turns

In what field does a stationary particle experience a force

electric field

what does emf do

emf creates a potential difference

which direction do magnetic field lines go

from north to south

which direction do electric field lines go

from positive to negative

acids are…

proton donors

bases are…

proton acceptors

properties of acids

turn litmus indicator (purple litmus) red tend to be corrosive taste sour react with bases solutions have a pH below 7.0 solutions conduct an electric current

properties of bases

turn litmus indicator (purple litmus) blue are caustic and feel slippery taste bitter react with acids solutions have a pH above 7.0 solutions conduct an electric current

A conjugate acid-base pair is?

two molecules or ions that differ by one proton (H+).

Amphiprotic substances

can behave as either an acid or a base.

Monoprotic acids can…

donate only one proton

polyprotic acids

can donate more than one proton from each molecule

Quarks

Up down strange charm top bottom

In a DC motor commutators are used

So the rotor keeps spinning in the same direction

in Chadwick’s experiment what did the paraffin wax provide

A source of protons

Milikans oil drop experiment

Oil drop suspended in electric field

what does a geiger counter do

Detects ionising radiation

Name two atmospheric pollutants

Sulfur dioxide(burning fossil fuels like coal) and nitrogen oxides(combustion in vehicles)