Physic key notes

Question 1

energy pathways

Answer 1

mechanical, electrical, heat and radiation

Question 2

reduce dissipation of energy

Answer 2

lubrication and thermal insulation

Question 3

in melting and boiling

Answer 3

1. bonds are broken between particles
2. internal energy increases
3. temperature in constant because the energy is being used to break intermolecular bonds

Question 4

background radiation

Answer 4

constant low level environmental radiation

Question 5

nuclear fission

Answer 5

one large unstable nucleus splits to make two smaller nuclei

Question 6

nuclear fusion

Answer 6

two small nuclei join to make one large nucleus

Question 7

what is used to detect radiation

Answer 7

geiger muller tube

Question 8

tracers

Answer 8

isotopes with small half lives injected allowed to circulate and collect in damaged areas

Question 9

thermistor

Answer 9

as temperature increases resistance decreases

Question 10

LDR

Answer 10

as light increases resistance decreases

Question 11

series

Answer 11

potential difference is shared across components
current is the same

Question 12

parallel

Answer 12

total current is the sum of the current across each component
voltage is the same at all points
total resistance of two resistors is less than the resistance of the small resistor

Question 13

factors increasing resistance

Answer 13

decreasing cross sectional area
increasing length
increasing temperature

Question 14

live wire

Answer 14

brown carries alternating current

Question 15

earth wire

Answer 15

yellow and green in safety wire to stop the wire from becoming live

Question 16

neutral wire

Answer 16

blue completes the circuit