PAPER 1 all topics

what is the equation for efficiency

efficiency (0….) = useful energy transferred out (J) / total energy transferred in (J)

what are the circuit symbols

what is potential difference

work done / energy transferred measured in volts

what is current like in a series circuit

the same everywhere

what is needed for current to flow

voltage to push current through components

how to improve efficiency when there is friction between moving parts

oil parts so they move more easily

how to improve efficiency when hot objects transfer energy to surroundings, wasting it

use an insulator to stop heat escaping

how to improve efficiency when there is air resistance from an object which oppose motion

streamline the object

how to improve efficiency when there is sound created by machinery

fix machinery in place or cushion parts

what is electric current

rate of flow of charge

what does a sankey diagram look like

what does a sankey diagram show

efficiency

what does a risk assessment table look like

hazard risk safety precaution

what is current like in a parallel circuit

all current into a junction adds up to all the current leaving it and the total current supplied is split between the components on different loops

what are the different variables for a test of how good an insulator is

independent variable is type of insulator dependent variable is temperature change and control variable is starting temperature amount of water and thickness of insulator

what does an insulator do

reduce flow of heat

how can a polythene rod be used to pick up a small piece of paper using friction

the rod is positively charged from friction so attracts the negative electrons in paper causing the paper to attract to the rod

what is specific heat capacity

the amount of energy needed to raise 1kg of something by 1c

what is the symbol equation for specific heat capacity

ΔE = mcΔθ

what is the word equation for specific heat capacity

change in joules = mass x specific heat capacity x temperature change

what is specific heat capacity measured in

c = J/kgc

what creates a potential difference

transfer of electrons due to a frictional force

how does a battery work

a battery is full of chemicals so energy is shifted from the chemical store of the battery to the moving charge and the charge moves in all the circuit at once. energy is shifted from the moving charge to the component to make it work

what is beta radiation

a neutron becomes a proton and an electron is emitted from the nucleus

how does beta radiation change mass and atomic number

atomic number increases by 1 and mass number stays the same

what is the relative mass of beta radiation

very small

how far can beta radiation travel in air

1m

what is the charge of beta radiation

\-1

what absorbs beta radiation

thin about 2mm of aluminium

what is the penetrating power of beta radiation

medium or mid

what is the ionising power of beta radiation

medium or mid

what is alpha radiation

a helium nucleus or alpha particle of 2 protons and 2 neutrons is emitted from the nucleus

how does alpha radiation affect mass and atomic number

atomic number decreases by 2 and mass number decreases by 4

what is the relative mass of alpha radiation

4

what is the charge of alpha radiation

\+2

how far can alpha radiation travel in air

up to 5cm

what absorbs alpha radiation

paper

what is the penetrating power of alpha radiation

weak or low

what is the ionising power of alpha radiation

high

what is gamma radiation

electromagnetic radiation is emitted from the nucleus

how does gamma radiation affect mass and atomic number

it doesn’t

what is the relative mass of gamma radiation

0

what is the charge of gamma radiation

0

how far can gamma radiation travel in air

over 1km

what absorbs gamma radiation

thick 10cm of lead or thick 50cm of concrete

what is the penetrating power of gamma radiation

strong or high

what is the ionising power of gamma radiation

low

what is ionisation

when electrons are removed from an atom by nuclear radiation

what is neutron emission

a neutron is emitted from the nucleus

how does neutron emission affect atomic and mass number

atomic number stays the same and mass number decreases by 1

what is the potential difference and current of batteries and cells

they have constant or direct potential difference so current always flows in the same direction which is called direct current DC

how does temperature affect pressure

more kinetic energy means faster moving particles and more collisions with each other and the edge. as they collide the force increases and more force in the same volume means higher pressure

what is count rate

number of decays per second recorded by a detector in one area

what is temperature

measure of average kinetic energy of particles

what happens to volume when pressure increases

volume decreases because the gas particles are forced closer together

what happens to volume when pressure decreases

volume increases because the gas particles can now move farther apart

how does increasing temperature affect brownian motion

when temperature increases brownian motion because particles have more kinetic energy so move faster and there are more collisions

what is boyle’s law

boyle's law states that for a gas at a constant temperature pressure × volume is also constant

what is resolution

the smallest change a device can detect

what is the symbol equation for density

p = m/v

what is the word equation for density

density kg/m3 = mass / volume

what is elastic potential

something stretching or contracting or changing shape

what is thermal or internal energy

something heating or cooling or changing state

what is chemical energy

a chemical reaction taking place

what is gravitational potential

something changing height or 2 masses getting closer

what is kinetic energy

something getting faster or slower

what is the potential difference across components in a parallel circuit like

the total potential difference across all the components in one loop sums to the potential difference of the cells

how would you find out the peake potential difference on an oscilloscope

the highest the line goes is the peak potential difference

what is a closed system

a system where energy cannot enter or leave

what is the resistance of a circuit

how difficult it is for current to flow through a circuit

what is resistance measured in

ohms Ω

what is the potential difference across the components in a series circuit like

the total potential difference across all the components sums to the potential difference of the cells

what does directly proportional look like on a graph

line of best fit will go through the origin

describe current through an ohmic resistor

it is directly proportional to the potential difference across it

how can you change the resistance of a wire

change its cross sectional area or its material or its length or its temperature

what is conservation of energy

energy cannot be created or destroyed but it can be stored or transferred between stores or dissipated

how many millivolts in a volt

1000 mV in 1V

how many cm3 in 1m3

1000000cm3 or 1 x 106 in 1m3

what is parallax error

when an object looks a different size or position when viewed from different angles

what is inversely proportional

when you double one you half the other and you can prove this by multiplying them together to get a constant. y = 1/x

what is brownian motion

smoke particles moving around in a random zig zag dance

how do you find the density of irregular shaped objects

1. measure the mass of the object and record
2. fill displacement can with water and put empty beaker under spout so water should drip from the spout into the beaker
3. when water stops dripping from the spout put a measuring cylinder underneath the spout
4. tie the object to a string and use the string to gently lower it into the water until it is just submerged
5. collect the water which comes out and measure it and record this volume as the amount of ml of water which came out is the volume of the object in cm3
6. divide the mass by the volume to get the density in g/cm3

explain electron energy level stuff

when an electron absorbs an electromagnetic wave it gives it energy which causes it to move to a higher energy level further away from the nucleus. when it has an energy crash it jumps back down to a lower energy level releasing energy and electromagnetic radiation

what is electrostatic potential

charges moving closer together or further apart

what is the equation for resistance

resistance = voltage / current (VIR)

what does the earth wire do

safety feature to stop the case of the appliance going live

what is the potential difference of the earth wire

0V

what is activity

the rate at which a source of unstable nuclei decay - the number of decays per second measured in becquerel Bq

what does the live wire do

carries alternating potential difference

what is the potential difference of the live wire

230V

describe mains electricity

it has an alternating potential difference and an alternating current AC meaning the current keeps changing from positive to negative and it keeps changing direction

why should an electrician not replace a shower until it is disconnected from the mains supply

because there is a big potential difference between the electrician 0v and the live wire in the shower of 230v so the current would flow through the electricians body to the earth if they touched it and they would get an electric shock

what does a fuse do

when current gets too large when there is a fault in an appliance the metal strip in the fuse melts and the circuit cannot flow so the appliance is turned off

what does the neutral wire do

completes the circuit

what is the potential difference of the neutral wire

about 0V

what is nuclear potential

nuclear decay or fission or fusion

what is magnetic potential

magnets moving closer together or further apart

what are cables made up of

earth neutral and live wires surrounded by different colours of plastic or rubber insulation to stop electric shocks and make them easily identifiable. copper is used for the wires because it is a good conductor of electricity

what is the equation for pressure

pressure Pa = force N / area m2

what are the different colours of insulation for each of the wires

earth is yellow and green striped neutral is blue and live is brown