Tag: concept of pressure

Questions Related to concept of pressure

Which of the following are units used to measure pressure?

  1. $kg$ ${m}^{-2}$

  2. pascal (Pa)

  3. newton per ${m}^{2}$

  4. joules


Correct Option: B,C
Explanation:

The pressure is the force per unit area. So, $P=F/A$

The unit of force is newton (N) and unit of area is $m^2$. 
Thus, the unit of pressure is $N/m^2$. 
Pascal is the SI unit of pressure. It is equal to one newton divided by one square meter. 

The SI unit of pressure is $N/m^2$.This unit is otherwise called ____________.

  1. Pascal

  2. Newton

  3. Joule

  4. None of these


Correct Option: A
Explanation:

Pressure is defined as force applied per unit area. Hence, its SI unit is $N/{ m }^{ 2 }$ or Pascal here,

         1 Pascal = 1 $N/{ m }^{ 2 }$.

Two women are of the same weight. One wears sandals with pointed heels while the other wears sandals with flat soles. Which one would feel more comfortable while walking on a sandy beach?

  1. The one with pointed heels

  2. The one with flat soles

  3. Both will feel similar comfort

  4. Can't say


Correct Option: B
Explanation:

Pressure(P)$=$$ \frac{Force(F)}{Area(A)}$

As both the women have same weight, so both of them will apply the same force on the ground. But flat soles having larger area compared to sandals with pointed heels, will exert lesser pressure compared to that of sandals having pointed heels. So, the sandals with pointed heels will sink more. Therefore, the woman having flat sole sandal will feel more comfortable while walking on a sandy beach.

Force acting per unit area is

  1. Acceleration

  2. Pressure

  3. Velocity 

  4. None


Correct Option: B
Explanation:

Pressure is defined as force per unit area. The standard unit for pressure is the Pascal, which is a Newton per square meter.

$P=\dfrac{F}{A}$

For an object sitting on a surface, the force pressing on the surface is the weight of the object, but in different orientations it might have a different area in contact with the surface and therefore exert a different pressure.

The pressure of the fluid acting sideways is known as its lateral pressure

  1. True

  2. False


Correct Option: A
Explanation:

pressure acting sideways is known as lateral pressure .

so option (A) is correct

Pressure is equal to

  1. $\dfrac{Force}{Area}$

  2. $\dfrac{Area}{Force}$

  3. $\dfrac{Thrust}{Area}$

  4. $\dfrac{Area}{Time}$


Correct Option: A
Explanation:

Pressure can be defined as the force per unit area which can be written as $\dfrac{Force}{Area}$.

Fill in the blank.

Pressure is a __________ quantity.

  1. Scalar

  2. Vector

  3. both A and B

  4. neither A nor B


Correct Option: A
Explanation:

Although Force and Area, both are vector quantities, pressure is a scalar quantity.

What is the relation between thrust and pressure?

  1. Pressure directly proportional to thrust

  2. Pressure indirectly proportional to thrust

  3. No relation

  4. none


Correct Option: A
Explanation:
Hence pressure=$P=\dfrac{Thrust}{Area}$
$\implies Pressure\propto Thrust$

Fill in the blank.

Pressure affects ________ substances.

  1. solid

  2. liquid

  3. gaseous

  4. solid, liquid and gaseous


Correct Option: D
Explanation:

Pressure affects substances in al the state whether it is liquid, solid or gaseous.

Pressure = ?

  1. force $\times$ area

  2. force / area

  3. mass / area

  4. area / force


Correct Option: B
Explanation:

Pressure is the force acting on a unit area of a surface it can be written as pressure  $= \dfrac{force}{area}$