Tag: physics

Questions Related to physics

Hydraulic press is based upon :-

physics pressure in fluids and atmospheric pressure hydraulic equipment applications of pascals law examples of hydraulic press

  1. Archimede's principle

  2. Bernoulli's theorem

  3. Pascal's law

  4. Reynold's number

Show answer
Correct Option: C
Explanation:

Hydraulic press works on Pascal's principle, which states - “pressure throughout a closed system is constant.” 


In hydraulic press, there is a piston at one end of the system having a small cross-sectional area. This piston is driven by a lever. The other end of the system has small-diameter tubing. 
When a fluid is displaced, either of the pistons is pushed inward. Small piston displaces a smaller amount of volume than the large piston for a given distance of movement. The displaced fluid volume is proportional to the ratio of pistons' head areas. Hence, smaller piston moves a large distance to move large piston significantly. The large piston movement distance is equal to small piston movement distance divided by the ratio of the pistons' head areas.

The working of hydraulic brakes is based on $Pascal's \ law.$

physics pressure in fluids and atmospheric pressure hydraulic equipment applications of pascals law examples of hydraulic press

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

hydraulic brakes are based on the pascal`s law and is used for amplifying the applied force to a given extent .

therfore option (A) is correct

.......................... is used to lift or support heavy objects and work on Pascal's law.

physics pressure in fluids and atmospheric pressure hydraulic equipment applications of pascals law examples of hydraulic press

  1. Hydraulic lift

  2. Hydraulic press

  3. Hydraulic brake

  4. All

Show answer
Correct Option: A
Explanation:

A hydraulic lift is used to lift or support heavy objects. It consists of two pistons of variying cross sectional areas.

A mechanical machine which is used to lift or compress large loads.

physics pressure in fluids and atmospheric pressure hydraulic equipment applications of pascals law examples of hydraulic press

  1. hydraulic press

  2. hydraulic lifts

  3. hydraulic brakes

  4. none

Show answer
Correct Option: A
Explanation:

A hydraulic press is a mechanical machine used to lift or compress large loads. A hydraulic press consist of two cylinders $C _1$ and $C _2$, fitted with pistons, valves and tubes.

................ works on the Pascal's law and is used in automobiles.

physics pressure in fluids and atmospheric pressure hydraulic equipment applications of pascals law examples of hydraulic press

  1. Hydraulic press

  2. Hydraulic lift

  3. Hydraulic jack

  4. All

Show answer
Correct Option: C
Explanation:

Hydraulic brake confirms to Pascal's law and is used in automobiles. It consist of a master cylinder filled with brake oil and provided with an airtight frictionless piston.

The pump tube of hydraulic press is of cross section area $a$ and is connected with a press tube of cross section area $A$ such that :

physics pressure in fluids and atmospheric pressure hydraulic equipment applications of pascals law examples of hydraulic press

  1. $a>A$

  2. $A>a$

  3. $A=a$

  4. None of the above

Show answer
Correct Option: B
Explanation:

In the construction of hydraulic press, release valve and press foot valves are there.

Hydraulic press consist of a pump tube of cross sectional area $a$ connected with a press tube of cross sectional area $A$ such that $A>a$.
The lower end of the pump tube is connected with a smaller tube which is further connected with an underground water tank.
At the junction of the pump tube and the smaller tube is fitted $a$ "pump foot valve" which opens in the upward direction only.

Discharge of centrifugal pump is

physics pressure in fluids and atmospheric pressure hydraulic equipment applications of pascals law examples of hydraulic press

  1. inversely proportional to diameter of its impeller

  2. inversely proportional to $diameter^2$ of its impeller

  3. directly proportional to (diameter)2 of its impeller

  4. directly proportional to diameter of its impeller

Show answer
Correct Option: B
Explanation:

Discharge of centrifugal pump is inversely proportional to square of the diameter of its impeller, thus option B is correct.

Hydraulic jacks works on which principle from below?

physics pressure in fluids and atmospheric pressure hydraulic equipment applications of pascals law examples of hydraulic press

  1. the pressure in closed container is the same at all points

  2. the pressure in closed container is not same at all points

  3. the pressure in closed container is opposite at all points

  4. None

Show answer
Correct Option: A
Explanation:

Hydraulic jacks works on the Pascal's law that the pressure in closed container is the same at all points.

Power required to drive a centrifugal pump is directly proportional to __________ of its impeller.

physics pressure in fluids and atmospheric pressure hydraulic equipment applications of pascals law examples of hydraulic press

  1. Cube of diameter

  2. Fourth power of diameter

  3. Square of diameter

  4. Diameter

Show answer
Correct Option: B
Explanation:

Power required to drive a centrifugal pump is directly proportional to the fourth power of the diameter of its propeller.

$\therefore$  Power     $P \propto  D^4$

The greater the differences in the areas of the cylinders, the greater the           force output of the big cylinder for hydraulic jack. Fill in the gap

physics pressure in fluids and atmospheric pressure hydraulic equipment applications of pascals law examples of hydraulic press

  1. Potential

  2. Kinetic

  3. Rotational

  4. Dynamic

Show answer
Correct Option: A
Explanation:

According to the Pascal's law       $\dfrac{F _1}{A _1} = \dfrac{F _2}{A _2}$
$\implies$   Greater the difference in the areas of the cylinder , greater is the force potential output of the big cylinder for hydraulic jacks.