Question

The area of the cross-section of press plunger of a hydraulic press is $4m^2$. It is required to overcome a resistive load of $400kgf$ on it. Calculate the force required on the pump plunger if the area of cross section of the pump plunger is $0.01m^2$

• A. 1kgf
• B. 10kgf
• C. 0.1kgf
• D. 100kgf

Answer 1

The correct option is A

1kgf

Let $F_{1}and{F}_2$ be the forces exerted and $A_{1}and{A}_2$ be the area of cross section of the pump plunger and the press plunger respectively.
We know that, $A_1=0.01m^2$, $F_2=400kgf$ and $A_2=4m^2$
By Pascals law,
Pressure on pump plunger = Pressure on press plunger
$\Rightarrow$$\frac{F_1}{A_1}=\frac{F_2}{A_2}$

$\Rightarrow$$\frac{F_1}{0.01}=\frac{400}{4}$

$\Rightarrow$ $F_1=100\times 0.01$ = 1 kgf