Energy and Light

Question 1

PAR light refers to electromagnetic energy with wave lengths from 380 - 750 nm. TRUE OR FALSE.

Answer 1

FALSE.
400nm-700nm.

Question 2

A greenhouse with sidewall vents is an example of a closed thermo-dynamic system. TRUE OR FALSE.

Answer 2

False. (*)

Question 3

Clarity is a glazing specification that…

Answer 3

indicates the percentage of the total amount of light transmitted through the material that is direct transmission

Question 4

The percentage of electromagnetic energy that is transmitted or reflected by an object is dependent on…

Answer 4

-the type of material its made from
-the angle of incidence of the incoming rays

Question 5

Thermal conductivity refers to the rate at which heat energy can be transferred through a material for every degree difference in temperature from one side to the other. TRUE OR FALSE.

Answer 5

True (*)

Question 6

Please select all that apply. The two main types of energy that we are concerned with in greenhouse management are…

Answer 6

-thermal energy
-electromagnetic energy

Question 7

The sun produces a spectrum of electromagnetic energy only in the UV and Visible Light wavelengths.

Answer 7

False. (*)

Question 8

Plants grown under UV-A and UV-B light tend to…

Answer 8

-have shortened stems with thicker leaves and cuticles to protect against the high energy light

Question 8

Electromagnetic energy is sometimes referred to as radiation.

Answer 8

True

Question 9

Two types of Infrared radiation that are important to greenhouse management are Near Infrared and Far Infrared radiation.

Answer 9

True

Question 10

Coatings that are added to a glazing material to change its properties can be sprayed on after the greenhouse is constructed.
TRUE OR FALSE.

Answer 10

True

Question 11

The second law of thermodynamics states that…

Answer 11

heat will transfer from objects or areas of high temperature to low temperature.

Question 12

It is always best to have glazing coatings and additives permanently manufactured into the product at the time of ordering.
TRUE OR FALSE

Answer 12

False

Question 13

UV-C light is beneficial to plant growth.
TRUE OR FALSE

Answer 13

False.

Question 14

Heat energy can be transferred by…

Answer 14

-conduction, convention and radiation

Question 15

The type of heat energy that is associated with a change of phase (ie solid <-> liquid <-> gas) is called…

Answer 15

latent heat

Question 16

When we study the transfers of all the light and heat energy between the internal and external greenhouse environments, we are studying the…

Question 17

Haze is a glazing specification that…

Answer 17

indicates the percentage of the total amount of light transmitted through the material that is diffuse

Question 18

Photosynthetically active radiation refers to the wavelengths of light that are primarily absorbed by chlorophyll. TRUE OR FALSE

Answer 18

True

Question 19

Light Transmission % is a glazing specification that…

Question 20

Please select all that apply. Which of the following features are characteristic of a proportional injector.

Question 21

Please select all that apply. Which of the following features are characteristic of a peristaltic dosing pump.

Question 22

A glazing material’s U-value…