Tag: physics

Questions Related to physics

Ice of water at $ 100^o $ is given 540 cal of beat and the steam formed occupation 1671 cc at the atmosphere pressure. Then workdone against atmosphere pressure in this procces is nearly

physics pressure common consequences of the atmospheric pressure atmospheric pressure and its consequences important points about atmospheric pressure

  1. 540 cal

  2. 500 cal

  3. 40 cal

  4. 100 cal

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Correct Option: A

In the above problem what is the pressure necessary to accomplish this task $(g=9.8\ m/s^{2})$

physics pressure common consequences of the atmospheric pressure atmospheric pressure and its consequences important points about atmospheric pressure

  1. $1.87\times 10^{5}\ N/m^{2}$

  2. $18.7\times 10^{5}\ N/m^{2}$

  3. $2.87\times 10^{5}\ N/m^{2}$

  4. $28.7\times 10^{5}\ N/m^{2}$

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Correct Option: C

What is the mass of $2$ litres of nitrogen at $22.4$ atmospheric pressure and $273\ K$ 

physics pressure common consequences of the atmospheric pressure atmospheric pressure and its consequences important points about atmospheric pressure

  1. $28\ g$

  2. $14 \times 22.4 g$

  3. $56\ g$

  4. $none\ of\ these$

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Correct Option: A
Explanation:

Consider STP conditions:
 
1) 1 mol = 22.4 L of gas; 1 mol of Nitrogen gas = 14 g
 
2) Therefore, 22.4 L Nitrogen gas = 14 g → 2 L Nitrogen = 1.25 g
 

3) This is at a standard pressure of 1 atm. So, 22.4 atm pressure corresponds to 22.4 × 1.25 = 28 g  

A sphere floats in water just submerged as shown in the diagram. If atmospheric pressure is neglected

physics pressure common consequences of the atmospheric pressure atmospheric pressure and its consequences important points about atmospheric pressure

  1. Force exerted by liquid on lower half of sphere is $\dfrac{4\rho\pi\ R^{2}}{3}g$

  2. Force exerted by liquid on lower half of sphere and upper half of sphere is same in magnitude

  3. Ratio of magnitude of forces exerted by liquid on lower and upper half of sphere is $5:1$

  4. Ratio of magnitude of forces exerted by liquid on lower and upper half of sphere is $4:1$

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Correct Option: C

A barometer tube, containing mercury, is lowered in a vessel containing mercury until only $50 cm$ of the tube is above the level of mercury in the vessel. If the atmospheric pressure is $75 cm$ of mercury, what is the pressure at the top of the tube

physics pressure common consequences of the atmospheric pressure atmospheric pressure and its consequences important points about atmospheric pressure

  1. $33.3 kPa$

  2. $66.7kPa$

  3. $3.33 MPa$

  4. $6.67 MPa$

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Correct Option: A
Explanation:

Since the mercury rises only $50cm$ it implies the rest of the excess atmospheric pressure is being countered by the pressure at the top of the tube.
So pressure at top=atmospheric pressure - $50cm$ of Hg=$(75-50)cm=25cm$ of Hg=$1/3\times 100kPa= 33.33kPa$

$2\ kg$ of water is converted into steam by boiling at atmospheric pressure. The volume changes from $2\times 10^{-3}\ m^{3}$ to $3.34\ m^{3}$. The work done by the system is about

physics pressure common consequences of the atmospheric pressure atmospheric pressure and its consequences important points about atmospheric pressure

  1. $-340\ kJ$

  2. $-170\ kJ$

  3. $170\ kJ$

  4. $340\ kJ$

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Correct Option: A

On the surface of earth, the atmospheric pressure is minimum at the sea-level.

physics pressure common consequences of the atmospheric pressure atmospheric pressure and its consequences important points about atmospheric pressure

  1. True

  2. False

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Correct Option: B

Match List I with List II and select the correct answer by using the codes given the lists.

List I List II
A. Baremeter $1$. Used for Measuring altitudes and angles in navigation and astronomy
B. Chronometer $2$. Used for measurement of angular distances between two digits
C. Sextant $3$. Keeps the accurate time as the one that is used to determine longitude at sea
D. Quadrant $4$. Used for measuring atmospheric pressure
$5$. An instrument used in the diagnosis of pregnancy
physics pressure common consequences of the atmospheric pressure atmospheric pressure and its consequences important points about atmospheric pressure

  1. A-$1$, B-$4$, C-$2$, D-$3$

  2. A-$4$, B-$2$, C-$5$, D-$1$

  3. A-$2$, B-$3$, C-$5$, D-$4$

  4. A-$4$, B-$3$, C-$2$, D-$1$

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Correct Option: D

As the vertical height from mean sea level increases, the atmospheric pressure decreases.

physics pressure in fluids and atmospheric pressure common consequences of the atmospheric pressure atmospheric pressure and its consequences important points about atmospheric pressure

  1. True

  2. False

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Correct Option: A
Explanation:

With increase in vertical height, the atmospheric pressure falls. Fall in pressure means that the temperature also falls. This is because pressure is directly proportional to Temperature and vice versa.

How does atmospheric pressure change with the change in altitude 

physics pressure in fluids and atmospheric pressure common consequences of the atmospheric pressure atmospheric pressure and its consequences important points about atmospheric pressure

  1. pressure increases

  2. pressure decreases

  3. pressure remains same

  4. cant say

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Correct Option: B
Explanation:

Pressure decreases with the increase in altitude.