CGP Paper 1

Question 1

air gets trapped between the beaker and its surroundings

explain how this reduces convection of energy being trapped away

Answer 1

the pockets of air cannot move which prevents convention currents from forming around the outside of a beaker

Question 2

give two dangers of exposure to ionising radiation

Answer 2

can cause tissue damage

can cause cell mutations

Question 3

explain why almost no light escapes from an optical fibre as a light ray travels along

Answer 3

angle of incidence hits the outer layer at an angle greater than the critical angle so it is totally internaly reflected so almost none escapes

Question 4

how to calculate the refractive index

Answer 4

n = sin I divided by sin R

Question 5

calculate the angle with refractive index

Answer 5

sin -1 (1 divided by n)

Question 6

critical angle equations

Answer 6

sin c = 1 divided by n

Question 7

describe how Microsoft oven heats food

Answer 7

it emits microwaves
it penetrates a few cm into the food before being absorbed by water molecules in the food
the energy is then conducted or conveyed to other parts of the food

Question 8

frequency wavelength speed

Answer 8

speed = wavelength x frequency

Question 9

mobile phones work by transmitting and receiving microwaves signals
why are people concerned

Answer 9

some microwaves are absorbed by molecules in the body and can heat human body tissue internally some people are worried that this might damage health