Relative humidity past year questions

Relative humidity     

Video 1: 

http://www.tubechop.com/watch/8792291

Q1: What is the difference between high and low relative humidity?

Video 2:

http://study.com/academy/lesson/what-is-humidity-definition-measurements-effects.html

Q2: How is relative humidity calculated?

Figure 1:

Q3: What is the relationship between Relative humidity and temperature?

1.		A group of students selected 12 sites around their school campus to carry out an investigation to test the given hypothesis: Hypothesis: Temperatures are higher nearer to buildings. They measured the distance from each site to the nearest building. At each site they measured temperature and relative humidity. Fig. 1 shows the temperature and relative humidity readings at the twelve sites. Site A B C D E F G H J K L M Distance from  Buildings (m) 32 2 3 5 1 17 9 2 10 24 30 42 Temp (0C) 28.2 28.5 29.1 28.1 28.9 28.2 28.4 28.8 28.6 28.3 28.1 28.0 Type of ground surface Grass Bush Con-crete Tar-mac Con-crete Trees Next to water Con-crete Grass Tar-mac Grass Tar-mac Relative Humidity (%) 73 77 73 73 76 73 75 77 75 77 76 75 Fig. 1
	a	Using Fig. 1, suggest another suitable hypothesis for the class to investigate.
		·        Relative humidity is affected by the type of ground surface ·        Temperature is affected by the type of ground surface                 Accept any other plausible answer
	b	Using Fig. 1, identify the instruments needed in this investigation.
		·        Digital thermometer ·        Hygrometer
	c	Suggest three reasons why temperatures vary around the school campus.
		·        Buildings / tarmac / concrete absorb / store heat from sun or internal heating system ·        Buildings radiate heat for small distance around them thus temperatures are higher nearer to buildings ·        Aspect / south facing / north facing / faces sun will have higher temperature ·        Sun: shade from sun/ shade by trees / buildings will have lower temperature ·        Wind: Shelter from wind / exposure to wind / shelter by trees/ buildings will result in different temperature ·        Different types of surface / e.g. some on grass and concrete
		3         Fig.3 shows an example of how relative humidity is calculated with a Relative Humidity table. a)      With the aid of Fig. 3, calculate the relative humidity for the following readings: ·         Temperature difference = 1°C  Relative Humidity = 91% [2] b)      Describe the advantages of using a digital thermometer and a hygrometer over a maximum-minimum thermometer and a wet and dry bulb thermometer.                           [4] ·         The digital thermometer and hygrometer can give instant readings. Thus, one does not have to work out the answer. ·         Easy / clear to read with a large digital readout  ·         One does not need to learn how to read a thermometer. ·         Parallax errors can be avoided since one does not have to read off thermometer. ·         Since exact figures are given, the measurements are more accurate. ·         Portable / can be used at more than one site ·         Safer to use as there is no mercury content [3]