Question Number 11:
As altitude increases, pressure
Option A: decreases exponentially.
Option B: decreases at constant rate.
Option C: increases exponentially.
As altitude increases, pressure decreases exponentially. Since pressure is given by density * gravity * height, both density and height decreases (that is, height above the point you measuring) so the decrease in pressure is exponential.
Question Number 12:
Lapse rate usually refers to
Option A: Density.
Option B: Pressure.
Option C: Temperature.
Temperature lapse rate is constant up to 36000ft -2degrees per 1000ft.
Question Number 13:
Temperature above 36,000 feet will
Option A: increase exponentially.
Option B: decrease exponentially.
Option C: remain constant.
Temperature lapse rate up to 36,000 feet (the tropopause) is approximately 2 degrees centigrade per 1000 feet. Above the tropopause it is constant.
Question Number 14:
With increasing altitude pressure decreases and
Option A: temperature decreases at the same rate as pressure reduces.
Option B: temperature decreases but at a lower rate than pressure reduces.
Option C: temperature remains constant to 8000 ft.
temperature decreases but at a lower rate than pressure reduces.
See a graph of pressure against altitude and temperature against altitude. Pressure decreases faster than temperature therefore pressure has a greater effect upon the performance of the aircraft.
Question Number 15:
What is the temperature in comparison to ISA conditions at 30,000ft?
Option A: -60°C.
Option B: 0°C.
Option C: -45°C.
ISA = 15°C temperature lapse rate is 2°C per 1000ft. Therefore 30000 = - 60 +15 = -45.
Question Number 16:
At what altitude is the tropopause?
Option A: 36,000 ft.
Option B: 57,000 ft.
Option C: 63,000 ft.
The tropopause is 36,000 ft. Above the tropopause is the stratosphere.
Question Number 17:
What approximate percentage of oxygen is in the atmosphere?
Option A: 12%.
Option B: 21%.
Option C: 78%.
21% oxygen, 78% nitrogen, 1% other gases.
Question Number 18:
Which has the greater density?.
Option A: Air at low altitude.
Option B: Air at high altitude.
Option C: It remains constant.
Air at low altitude.
Air density reduces with altitude.
Question Number 19:
At what altitude does stratosphere commence approximately?
Option A: Sea level.
Option B: 36,000 ft.
Option C: 63,000 ft.
The stratosphere is above 36,000 ft.
Question Number 20:
A pressure of one atmosphere is equal to
Option A: 14.7 psi.
Option B: 1 inch Hg.
Option C: 100 millibar.
One atmosphere is 14.7 psi.