Questions Related to physics

Multiple choice physics pressure pressure in air introduction to atmospheric pressure pressure exerted by air devices to measure pressure

State whether given statement is True or False
You find your mass to be $42$kg on a weighing machine. Is your mass more or less than $42$kg?

  1. True

  2. False

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When you weigh your body, an upward buoyant force acts on your body due to the air (a fluid) present around you. As a result, the body gets pushed slightly upwards, causing the weighing machine to show a reading slightly less than the actual value.

Multiple choice physics pressure pressure in air introduction to atmospheric pressure pressure exerted by air devices to measure pressure

State whether true or false:

A sheet of paper falls slower than one that is crumpled into a ball.

  1. True

  2. False

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Sheet crumpled into a ball has a small surface area as compared to the similar unfolded sheet. Therefore, unfolded sheet will experience more resistance due to air as compared to the sheet crumpled into a ball, inspite of same force of gravity acting upon them. It is larger resistance of air which slows down the unfolded sheet, and therefore it falls slower as compared to sheet crumpled into a ball.

Multiple choice physics pressure in fluids and atmospheric pressure pressure in air introduction to atmospheric pressure pressure exerted by air devices to measure pressure

The boiling point of a liquid can be raised by

  1. Increasing pressure

  2. Decreasing pressure

  3. Increasing the heat supply

  4. Increasing the quantity of the liquid

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

When water heats up the molecules move faster and faster and move farther apart, eventually becoming steam. When the pressure on the water is increased,  the molecules are more tightly held. This helps keep them from moving apart so it requires more heat to get them to "break free" and move apart. So, the higher the water pressure the higher the boiling point. 

Multiple choice physics pressure in fluids and atmospheric pressure pressure in air introduction to atmospheric pressure pressure exerted by air devices to measure pressure

Cooking is done fast in pressure cooker because

  1. The boiling point of water is lowered

  2. The boiling point of water is increased

  3. More pressure is the cooker cooks the food at 100C

  4. The boiling point remains the same but more steam cooks the food

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In a pressure cooker, as the pressure inside increases with time, the boiling point of water increases and hence is able to cook fast.

Multiple choice physics pressure in fluids and atmospheric pressure pressure in air introduction to atmospheric pressure pressure exerted by air devices to measure pressure

The air pressure inside out body is equal to the ____?

  1. in internal pressure

  2. atmospheric pressure

  3. both a and b

  4. none of the above

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The pressure inside our bodies is equal to the atmospheric pressure and cancels the pressure from outside. we do not get crushed under the atmospheric pressure.

Multiple choice physics pressure in fluids and atmospheric pressure pressure in air introduction to atmospheric pressure pressure exerted by air devices to measure pressure

Ink does not spill out of an ink dropper when the atmospheric pressure and ____ pressure are equal.

  1. external

  2. internal

  3. air

  4. vaccuum

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

As the pressure inside the dropper, i.e, the internal pressure and the atmospheric pressure become equals,  ink does not spill out.

Multiple choice physics pressure in fluids and atmospheric pressure pressure in air introduction to atmospheric pressure pressure exerted by air devices to measure pressure

State whether the following statements are true or false?
(i) the pressure inside our body is equal to the atmospheric pressure
(ii) pressure is inversely proportional to the area.

  1. Both are true

  2. Both are false

  3. (i) True<div>(ii) False</div>

  4. (i) False<div>(ii) True</div>

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

(i) True, because we do not get crushed as the pressure inside and atmospheric pressure becomes equal.

(ii) True, as $pressure=\dfrac{force}{area}$. So, for constant force, $pressure\propto\dfrac{1}{area}$

Multiple choice physics pressure in fluids and atmospheric pressure pressure in air introduction to atmospheric pressure pressure exerted by air devices to measure pressure

While filling a syringe with liquid which of the following is true for pressure inside the barrel and the atmospheric pressure acting on the liquid?

  1. pressure inside the barrel is less than atmospheric pressure

  2. pressure inside the barrel is more than atmospheric pressure

  3. pressure inside the barrel is same as atmospheric pressure

  4. none of these

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

When the plunger is pulled up in the barrel, the pressure inside the barrel is much less than atmospheric pressure. As a result atmospheric pressure forces the liquid to rise up in the syringe.