Whole of aqa physics

Question 1

What is wasted energy

Answer 1

When energy is dissipated into the surroundings

Question 1

How to be energy efficient in a house

Answer 1

Cavity wall insulation
double glazing
loft insulation
carpets
curtains
draft excluders

Question 2

What does renewable mean

Answer 2

not going to run out can get more e.g. solar wind water. also dont release co2

Question 3

What is an Independent Variable

Answer 3

Something that is changed

Question 4

What is an dependent variable

Answer 4

something that is measured

Question 5

what is a controllable variable

Answer 5

something that is kept the same

Question 6

What is finite

Answer 6

going to run out cant get more e.g. fossil fuel coal oil gas

Question 7

Disadvantages to solar power

Answer 7

Doesn’t work during night and isn’t god on cloudy days or wintry days and expensive

Question 8

Disadvantages to wind power

Answer 8

People dont like them dont work on non windy days

Question 9

Disadvantages to tidal and wave energy

Answer 9

can be disruptive to environment and hydro electric dam involves flooding large area disrupts habitats

Question 10

Disadvantages to geothermal energy

Answer 10

Only used in volcanic countries

Question 11

Advantages to fossil fuels

Answer 11

Readily available cheap source of electricity
things like coal power stations have a short start up time

Question 12

Disadvantages of fossil fuels

Answer 12

Take millions of years to form
Heavily polluting

Question 13

What is charge

Answer 13

Value for electricity flowing in a circuit
Measured in coulombs, C

Question 14

What is current

Answer 14

Flow of electrons
Measured in An ampere or amp,

Question 15

What is potential Difference

Answer 15

Pushes current around
Measured in Volts

Question 16

What is Resistance

Answer 16

slows downs the current
Measured in ohms

Question 17

Equation for Power

Answer 17

P(watts)= V(volts) x I(amps)
power= potential difference x current

Question 18

Equation for power current squared

Answer 18

p= I^2 x R
power= amps x ohms

Question 19

Equation for energy

Answer 19

E= P x T

Power x time
Joules=power x watts

Question 20

Equation for energy (2)

Answer 20

E= Q x V
energy= charge x potential diff
Q= coulombs

Question 21

Step up transformer

Answer 21

Turns low voltage into high voltage so energy can move through a system with less energy loss= more efficient

Question 22

Step down transfromer

Answer 22

takes High voltages and turns it down to low voltage to allow it to be safe in our homes

Question 23

What is density

Answer 23

Mass in a set volume

Question 24

equation for density

Answer 24

p=m/v P=density kg/m^3 M=mass V=volume

Question 25

Specific heat capacity

Answer 25

Amount of energy needed to raise the temperature of 1kg of the substance by 1degree Celsius.

Question 26

Equation for SHC

Answer 26

change in energy= mass x SHCx Change in temp Triangle e= m x c x triangle o

Question 27

Specific Latent Heat

Answer 27

Amount of energy required to change the state of 1kg of the substance with no change in temperature.

Question 28

Equation for specific latent heat

Answer 28

E= m x l energy=mass x specific latent heat j=kg x J/kg

Question 29

Internal Energy

Answer 29

The total energy stored inside a system by the particles that make up the system due to their motion and positions

Question 30

What is an ion

Answer 30

an atom that has lost or gained an electron

Question 31

What is an Isotope

Answer 31

an atom that has diff number of neutrons but same protons and electrons

Question 32

History of the atom

Answer 32

Rutherford- positive centre Chadwick=neutrons Bohr-nuclear model

Question 33

Alpha Radiation (helium nuclei)

Answer 33

Radiation is large Highly ionising No penetration Paper and skin can stop alpha

Question 33

Plum pudding model

Answer 33

A large positive blob with negative bits dotted throughout

Question 34

Beta Radiation (electron)

Answer 34

Radiation is moderate Moderately ionising Moderately penetrating Aluminium can stop beta

Question 34

Gamma Radiation (electromagnetic wave)

Answer 34

Radiation is small Not Ionising Highly penetrating Lead can stop gamma

Question 35

What does ionising mean

Answer 35

How good it is at turning something into an ion

Question 36

What measures Radiation

Answer 36

Geiger muller tube

Question 37

Unit for radiaiton

Answer 37

Becquerels (bq)

Question 38

Half life

Answer 38

Time it takes the radioactive atom to decay