P1, 2, 3

?
  • Created by: xxemilyxx
  • Created on: 09-06-14 15:34
Microwaves are absorbed by...
fat and water molecules.
1 of 43
What do cavity walls do?
Reduce conduction, foam reduces convection.
2 of 43
What does double glazing do?
Reduce conduction
3 of 43
The darker the colour on the thermogram the...
colder the parts are
4 of 43
Law of reflection:
Angle of incidence equals angles of reflection
5 of 43
Total internal reflection can only happen if
the substance it is in is denser than the substance it is heading towards
6 of 43
If the angle of incidence is greater than the critical angle
it is total internal reflection - no light comes out
7 of 43
If the angle of incidence is equal to the critical angle
The ray would travel along the surface with a bit of internal reflection
8 of 43
If the angle of incidence if less than the critical angle
Most light would be refracted outside with some internal reflection
9 of 43
The bigger the gap or the smaller the wavelength the...
less diffraction
10 of 43
If a wave meets a denser medium at an angle...
the wave is refracted
11 of 43
If a wave travels through a denser medium it
has a shorter wavelength
12 of 43
What signals are reflected off the ionosphere?
Short-wave signals
13 of 43
What signals diffract around the Earth?
Long-wave signals
14 of 43
What waves diffract around hills?
long wavelength waves
15 of 43
What is the ionosphere?
layers of ionised atoms caused by UV radiation from the sun.
16 of 43
What waves are gradually refracted back to Earth?
Waves with higher frequencies or that are transmitted at higher angles of elevation.
17 of 43
What happens to waves with lower frequencies or that are transmitted at a lower angle when they reach the ionosphere?
They are quickly refracted back to Earth.
18 of 43
What waves are used for satellite communication?
Microwaves.
19 of 43
How do photocells work?
The silicon absorbs the light energy knocking loose electrons.
20 of 43
What is passive solar heating?
When energy from the sun is used to directly heat something.
21 of 43
What is the dynamo effect?
Moving an electrical conductor through a magnetic field. using electromagnetic induction to create kinetic energy.
22 of 43
Why are step-up transformers used?
To increase the voltage, keeping the current low as a higher current is inefficient because it loses energy as heat.
23 of 43
Why is AC mainly used?
Transformers only work with AC.
24 of 43
What is off-peak electricity?
Energy supplied at night. + cost effective -higher risk of fire as you will be asleep
25 of 43
What is the greenhouse effect?
Infrared radiation emitted from the Earth is absorbed by atmospheric gases (C02, methane etc.), they then re-radiate in all directions including back to earth .
26 of 43
What causes nuclear radiation?
When an unstable nucleus decays it gives off radiation.
27 of 43
How can nuclear radiation cause ionisation?
The radiation causes atoms to lose or gain electrons. Ionisation can initiate chemical reactions between atoms.
28 of 43
Alpha particles ...
Made up of 2 protons and 2 neutrons. Are stopped by paper or skin. They are strongly ionising.
29 of 43
Beta particles ...
Just electrons, small Are stopped by a thin sheet of metal.
30 of 43
Gamma rays...
No mass, no charge, weakly ionising. Are stopped by thick concrete or a few centimetres of lead.
31 of 43
Smoke detectors use ...
Gamma rays which ionises the air so a current flows between the electrodes. When there's smoke it absorbs the radiation so the current stops and the alarm goes off.
32 of 43
Beta radiation is used for..
Tracers- it is swallowed. and thickness gauges.
33 of 43
Gamma is used to...
Sterilise medical instruments and are directed at cancer cells to kill them.
34 of 43
How does nuclear power work?
It uses uranium as fuel, its atoms are split into two in nuclear fission which releases lots of energy which is then used to produce steam to drive a turbine to turn the generator.
35 of 43
Advantages of nuclear power:
Produces lots of energy without producing lots of C02, Nuclear fuel is cheap and less is needed for 1 joule, There's still lots of uranium left in the ground, uranium can be reprocessed.
36 of 43
Disadvantages of nuclear power:
Expensive to build and maintain, processing uranium causes pollution, radioactive waste is dangerous.
37 of 43
Plutonium is used to...
make nuclear bombs.
38 of 43
What force causes a circular motion?
Centripetal force
39 of 43
What are comets?
Balls of rock, dust and ice that orbit the Sun in an elongated elipses
40 of 43
Objects that are shifted to the red end of the spectrum...
are moving away from us very quickly (distant galaxies)
41 of 43
Terminal speed is
when resistance = weight
42 of 43
ABS brakes...
automatically pump on and off to prevent skidding and shorten braking distance
43 of 43

Other cards in this set

Card 2

Front

What do cavity walls do?

Back

Reduce conduction, foam reduces convection.

Card 3

Front

What does double glazing do?

Back

Preview of the front of card 3

Card 4

Front

The darker the colour on the thermogram the...

Back

Preview of the front of card 4

Card 5

Front

Law of reflection:

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 P1, 2, 3 resources »