P2

?
how does a photocell work
absorbs light energy from the sun, electrons are knocked loose from the silicon crystals. this flow of charge is called an electric current
1 of 57
3 things the power of a photocell depends on
surface are exposed, distance from light source & intensity of light source
2 of 57
how can the power output of a photocell be maximised
if it follows the sun
3 of 57
what can a curved mirror be used to do
focus the sun's light
4 of 57
what does passive solar heating mean
a device that traps energy from the sun but doesnt distribute or change the energy
5 of 57
advantage & disadvantage of wind turbines
adv= renewable disadv=dependant on the wind
6 of 57
explain the dynamo effect
producing electricity by moving a wire/coil near a magnet. the wire cuts through the magnetic field and current is produced in the wire
7 of 57
3 ways to increase curren t in dynamo effect
stronger magnet, more coils & moving coils faster
8 of 57
what current do batteries produce
direct current (DC)
9 of 57
what current do generators produce
alternating current (AC)
10 of 57
what is meant by alternating current
direction of current is continually changing everytime the coil changes direction
11 of 57
give an example where the dynamo effect is used
AC generator
12 of 57
what is the national grid and what do they do
network of cables that connect power cables to consumers
13 of 57
how do nuclear power stations produce electricity
feul rods of uranium release energy (fission) as heat to make steam which makes turbines turn
14 of 57
what is the greenhouse effect
short wavelengths from the sun can pass through the atmosphere, earth absorbs it. As the earth is cooler than the sun so it emits longer wavelengths than the sun, so the rays cannot leave atmosphere, which then heats up
15 of 57
3 examples of greenhouse gases
CO2, water vapour, methane
16 of 57
Reason for climate change
fossil feuls burning
17 of 57
what is an electric current
flow of electrons
18 of 57
what does a transformer do
increases/decreases the voltage of supply
19 of 57
why do transformers increase the voltage
reduces energy loss
20 of 57
what happens to the current when the voltage increases
decreases
21 of 57
3 energy sources
fossil feuls, biomass & renewable sources
22 of 57
3 types of nucleur radation
alpha, beta gamma
23 of 57
what is ionisation
when atoms lose and gain electrons producing positively and negatively charged ions
24 of 57
why can ionisation be harmful in the body
damages cells
25 of 57
one use of alpha radation
smoke alarms
26 of 57
how does a smoke detector work
the radiation emitted causes ionisation to take place. positive and negative ions are attracted to oppositely charged electrodes in the fire detector, this causes a current. when smoke enters between the electrodes, less ionisation takes place. alarm
27 of 57
one use of beta radiation
paper thickness gauge
28 of 57
how does a paper thickness gauge work
beta radiation passing through paper, some is absorbed. when thickness of paper increasses less radiation gets through, a signal is sent telling rollers to move closer, recuding thickness of the paper
29 of 57
one use of gamma radiation
treat cancer
30 of 57
how does using gamma radaiton be used to treat cancer
high, calculated dose, is aimed at the tumour, so only cancerous cells are destroyed not healthy ones
31 of 57
what can be used to test the penetrating power of radiaton
geiger counter
32 of 57
what radiation is stopped by paper
alpha
33 of 57
what radiation is stopped by aluminium
beta
34 of 57
what radiation is stopped by lead
gamma
35 of 57
which radiation has the most ionising power
alpha
36 of 57
one waste product from nuclear powerstations and what it can be used for
plutonium & nucleur bombs
37 of 57
one adv & disadv of nuclear power
adv= doesnt pollute disadv+waste is radioactive
38 of 57
what is a comet's tail made of
the core evaporating in the sunlight
39 of 57
what are the eight planets
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune
40 of 57
what is an elliptical orbit
shaped like an egg
41 of 57
why do planets stay in their orbits
larger objects= inward pull force due to gravity (centripetal force)
42 of 57
what is a light year
distance light travels in a year
43 of 57
at what speed do radio waves travel @
speed of light
44 of 57
how is a moon formed
two planets collided, iron cores merged to form core of the earth, less dense material flew off and now orbits the earth (the moon)
45 of 57
what are asteroids
rocks leftover from the formation of the solar system
46 of 57
3 things that could happen if an asteroid collides with earyh
ejection of hot rocks, fires & climate change
47 of 57
what is a comet
small body with a core of frozen gas and sut
48 of 57
what does neo mean
near earth object
49 of 57
3 ways to reduce threat of an neo
survey, monitor, deflect
50 of 57
what have scientists noticed about the light from more distant galaxies
more red shifted
51 of 57
further planets are moving ---- away from us
faster
52 of 57
what type of rasdiation is also recieved from all parts of the universe
microwave
53 of 57
what is the life of a star
protostar, main sequence star, red giant, planetury nebula, white dwarf
54 of 57
what did nicolas copernicus claim
earth and other planets orbit sun
55 of 57
what did galileo gaslilei do
used telescope to see that venus had 'phases' like the moon, convinving him that plaents do orbit the sun
56 of 57
how are blackholes formed
at the end of the life of heavyweight star
57 of 57

Other cards in this set

Card 2

Front

3 things the power of a photocell depends on

Back

surface are exposed, distance from light source & intensity of light source

Card 3

Front

how can the power output of a photocell be maximised

Back

Preview of the front of card 3

Card 4

Front

what can a curved mirror be used to do

Back

Preview of the front of card 4

Card 5

Front

what does passive solar heating mean

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Physics resources:

See all Physics resources »See all all of p2 resources »