Question

In a Bramah press a force of 10 kg. wt is applied on a piston of area of cross section 5cm², then the upward thrust exerted by the piston of area of cross section 50cm² is ___ kg.wt 

(1) 10 

(2) 100 

(3) 1000 

(4) 1

Answer 1

Correct option is (2) 100 

Given that in a Brahmas press a force of 10 kg wt, is applied on a piston of area of cross section 5 cm². Here, the force is 10 kg wt and area of cross section or area is 5 cm.

Pressure is defined as force per unit area. And it is a scaler quantity.

Pressure = Force/Area

Substitute the values,

Pressure = 10/5 kg wt/cm²

Pressure = 2 kg wt/cm²

Now, in second case we need to find out the upthrust force if the area of cross section is 50 cm². From above pressure is 2 kg wt/cm². Substitute the values to get the value of force.

Force (upthrust) = 50 cm² x 2 kg wt/cm²

Force (upthrust) = 100 kg wt .

Therefore, the upward thrust exerted by the piston of area of cross section 50 cm² is 100 kg wt.