Consequences of Atmospheric Pressure

Q.

How is water drawn up from a well by a water pump ?

Q.

Why does the liquid rise in a syringe when its piston is pulled up?

Q.

The reason we are not crushed under the weight of the air is, that the pressure inside our body is equal to the atmospheric pressure and cancels the pressure being exerted from outside.

1. True

2. False

Q. Pressure increases with height. True or False?

1. True
2. False

Q.

Why two holes are made in a sealed tin cane to take out the oil from it?

Q.

Explain

Two holes are made in a sealed oil can to remove oil from it

Q. In a functional siphon, water rushes from the reservoir to the siphon because ______ .

1. the pressure in siphon is zero
2. the pressure in siphon is higher than the atmospheric pressure
3. the pressure in siphon is lower than the atmospheric pressure
4. the pressure in siphon becomes equal to the atmospheric pressure

Q.

Explain the following :
(i) A balloon collapses when air is removed from it.
(ii) Water does not run out of a dropper unless its rubber bulb is pressed.
(iii) Two holes are made in a completely filled sealed tin can to take out oil from it.

Q. A boat floating in a tank is carrying passengers. If the passengers drink some water, what will happen to the water level of the tank?

1. rises
2. falls
3. remains unchanged
4. depends upon the atmospheric pressure

Q.

The reason we are not crushed under the weight of air is that the pressure inside our body is equal to the atmospheric pressure.

1. True

2. False

Q. We are not crushed under the weight of air, as the pressure inside our body is to the atmospheric pressure.

1. greater
2. lesser
3. equal

Q.

A balloon collapses when air is removed from it. Explain.

Q. Name the instrument which is used to measure atmospheric pressure.

1. Barometer
2. Thermometer
3. Manometer
4. Speedometer

Q. When the temperature of air over a region increases, the atmospheric pressure .

1. increases
2. decreases
3. remains same.

Q.

What is meant by atmospheric pressure? Mention three examples to illustrate its effect.

Q.

To what extent the atmosphere is extended above the surface of the Earth, assuming the density of air to be uniform [1.3 kg/m³] and pressure at the surface of Earth to be 10⁵ Pa. (Also assume the Earth to be perfectly spherical and no variation in g due to height.)

1. 6 km < h < 7 km

Q. In the siphon system shown below, v refers to velocity and P refers to pressure. Then:

1. $v_E>v_A$
2. $P_D=P_0-pg(h_1+h_2)$
3. $v_A=v_B=v_E$
4. $v_E=5v_A+v_B$

Q. Figure shows a siphon. The liquid shown is water. The pressure difference $P_B-P_A$ between the points $A$ and $B$ is

1. $3000N/m^2$
2. $100N/m^2$
3. zero
4. $400N/m^2$

Q.

Siphoning is due to the difference in weight of the water columns of the "U" shaped tube.

1. True

2. False

Q. A thin square plate of side $4m$ is placed horizontally $2m$ below the surface of water. Calculate the thrust on one of the surface of the plate.
(Given: Atmospheric pressure, $P_{atm}=1.013\times {10}^{5}N/m^2$
Density of water, ${\rho }_w$ = $1000kg/m^3$,
Acceleration due to gravity, $\left(g\right)=9.8m{s}^{-1}$)

1. $19.344\times {10}^{5}N$

2. $19.344\times {10}^{3}N$

3. $17.344\times {10}^{5}N$

4. $21.344\times {10}^{5}N$

Q. When the temperature of air over a region increases, the atmospheric pressure .

1. increases
2. decreases
3. remains same.

Q. A drinking straw works on the pressure exerted by the atmosphere on the liquid which the straw is put into.

1. False
2. True

Q.

The reason we are not crushed under the weight of air is, that the pressure inside our body is equal to the atmospheric pressure.

1. True

2. False

Q.

The reason we are not crushed under the weight of air is that the pressure inside our body is equal to the atmospheric pressure.

1. True

2. False

Q. Figure shows a siphon. Choose the wrong statement ($P_0$ is atmospheric pressure)

1. Siphon works when $h_3>0$
2. Pressure at point $2$ is $P_2=P_0-\rho g{h}_3$
3. Pressure at point $3$ is $P_0$
4. None of the above

Q. A ${16cm}^3$ volume of water flows per second through a capillary tube of radius r cm and of length 1 cm, when connected to a pressure head of h cm of water. If a tube of the same length and radius r/2 is connected to the same pressure head, find the mass of water flowing per minute through the tube

1. 80 gram/min
2. 60 gram/min
3. 70 gram/min
4. 50 gram/min

Q. A column of air extending up to height of the atmosphere exists on an area of $100c{m}^2$ exists above our head. Why don't we get crushed?

1. The pressure inside his body is equal to the atmospheric pressure.
2. The pressure inside his body is higher than the atmospheric pressure.
3. His skin is not sensitive enough to feel it.
4. The pressure inside his body is lower than the atmospheric pressure.

Q. Siphon will fail to work if

1. the densities of the liquid in the two vessels are equal
2. the level of the liquid in the two vessels are at the same height
3. both its limbs are of unequal length
4. the temperature of the liquids in the two vessels are the same

Q. A rubber sucker sticks to a surface due to the high air pressure acting on it from the surroundings.

1. False
2. True

Q. We are not crushed under the weight of air, as the pressure inside our body is to the atmospheric pressure.

1. greater
2. lesser
3. equal