# PTE Reading MCM #20: Atmospheric Pressure...

Reading: Multiple Choice, Multiple Answers #20 - Level 3 - Feeds Reading

> Read the text and answer the question by choosing all the options that are correct. More than one answer is correct, and a wrong choice costs a point.

Forces other than damaging winds are also at work inside tornadoes. Sometimes, as the writhing, twisting funnel passes over a house, the walls and ceiling burst apart as if a bomb had gone off inside. This explosion is caused by the low air pressure at the center of a tornado. The pressure at the center of a tornado is usually 13 pounds per square inch. However, inside the house, the air pressure is normal, about 15 pounds per square inch. The difference of 2 pounds per square inch between the inside and outside pressure may not seem like much. But suppose a tornado funnel passes over a small building that measures 20 by 10 by feet. On each square inch of the building, there are 2 pounds of pressure from the inside that is not balanced by air pressure outside the building. On the ceiling, that adds up to an unbalanced pressure of 57, 600 pounds. The pressure on the four walls adds up to 172,800 pounds. If windows are open in the building, some of the inside air will rush out through them. This will balance the pressure inside and outside the building. But if the windows are shut tightly, the enormous inside pressure may cause the building to burst. Unfortunately, heavy rain and hail often occur in thunderstorms that later produce tornadoes. So people frequently shut all windows to protect themselves. This may cause far worse damage later. For the same reason, tornado cellars must have an air vent. Otherwise, the cellar door might be blown out when a tornado passes over it.

Which of the following statements can be supported by the information given in the passage?

- The difference per square inch between the air pressure inside a building and the air pressure inside a tornado is of 2 pounds.
- According to passage, Tornadoes can destroy the building because the air pressure inside a tornado is less than the air pressure inside the building.
- The pressure on a building during a tornado can be relieved by closing the cellar.
- The passage talks about as how tornadoes can be prevented.

## Answer

- The difference per square inch between the air pressure inside a building and the air pressure inside a tornado is of 2 pounds.
- According to passage, Tornadoes can destroy the building because the air pressure inside a tornado is less than the air pressure inside the building.

## Explanation

The passage confirms that the pressure difference is 2 pounds per square inch and that the lower pressure inside a tornado relative to a building creates an explosive force.

## Hints

- Focus on the specific numerical values provided in the text regarding air pressure.
- Consider how the text explains the cause of structural failure during a storm.

[Practise this question with the exam timer](https://testmigo.com/pte/practice/reading-multiple-choice-multiple-answers/atmospheric-pressure-dynamics-in-tornadoes) - [All Reading: Multiple Choice, Multiple Answers questions](https://testmigo.com/pte/practice/reading-multiple-choice-multiple-answers)