Infrared (Required Practical)

Question 1

what does a leslie cube do

Answer 1

how much infared is emitted from different surfaces

Question 2

what are the 4 sides of the leslie cude

Answer 2

shiny metallic
white
shiny black
matt black

Question 3

what are the steps for the leslei cube practical

Answer 3

1. First, we fill the Leslie’s cube with hot vvater.
2. point an infrared detector at each of the four surfaces and record the amount of infrared emitted and make sure to keep the same distance between the leslie cude and the infared detector

Question 4

from most to least which surface releasesthe most amount of infrared emission

Answer 4

matt black
shiny black
white
shiny matallic

Question 5

what should you use if you dont have an infrared detector

Answer 5

use a thermometer with the bulb painted black but will not detect a major difference like the infrared detector

Question 6

how do you measure the absorbance of infrared by different surfaces

Answer 6

1. We have an infrared heater and on either side we have metal plates.
2. one plate is painted in shiny metallic paint and the other with mat black paint
3. On the other side of the plates, we have used Vaseline to attach a drawing pin.
4. switch on the heater and start the timer
5. The temperature of the metal plates increases as they absorb infrared.
6. We record the time it takes for the Vaseline to melt and the drawing pins to fall off.
7. we find that the drawing pin falls of the Matt black one first (because Matt black surfaces absorb more infrared than shiny metallic surfaces)
8. Matt black surfaces are much better at emitting and absorbing infrared than shiny metallic surfaces.