# Physics MCQ 6 Flashcards

Define critical temperature

Temperature above which a gas cannot be liquified

What is oxygens critical temperature and boiling point?

Critical temp: -118 degrees C

Boiling point: - 183 degrees C

Color of oxygen cylinder

Black body with white shoulders

Color of air cylinder

Grey body with white and black shoulders

How many atoms oxygen molecules form in

O2 and O3

What is absolute humidity?

Mass of water vapour present in a volume of air

What is the characteristic property of dew point?

Full saturation- 100% humidity

What do wet and dry hygrometers calculate?

Relative humidity

How does temperature affect the amount of water vapour present?

Amount of water vapour present in air is dependent on its VAPOUR PRESSURE.

Vapour pressure is proportional to temperature so warm air holds more water vapour.

What is the relative humidity of the trachea?

100% saturated

MRI: T/F

- Contain two electromagnets aligned perpendicularly
- Images are generated by amplifying signals produced by the precession of hydrogen atoms.
- Magnetic flux density of?
- Relies on absorption and reabsorbtion of energy from radio frequency waves
- Liquid helium is used in magnets to reduce resistance in the electromagnet

- True
- True
- Up to 1 Tesla
- True
- True

Is p<0.05 more significant than p<0.01?

No, p< 0.05 means that after the statistical test there is less than 5% chance if the null hypothesis being rejected by chance.

Therefore p< 0.01 (less than 1% chance) is more significant than p < 0.05.

In positively skewed data is the median greater than the mean?

Positively skewed data is skewed to the right, so the mean tends to lie to the right of the median value

- is the lower of the two.

What percentage of the population lies within two standard deviations of the mean?

95%

The standard error of the mean is:

- the square root of the variance

- is the standard deviation divided by the square root of the degrees of freedom (the number of observations - 1)