Given that,
area of piston A =a1 = 2* 10-3 m2
force on piston A = f1 = 10N
the pressure exerted on liquid by the piston A will be :
A =f1/a1
= 10/2*10-3
=500 pa
The area of piston B, C, D = a2 = 5 *10 -3m2
force on these pistons = f2 = ?
pressure on A = pressure on B, using pascal's law .
we get
5000= f2/ A2
f2 = 5000 * 10-3
f2 = 25 N
hence, the pressure on A is 500 pa and force is 25 N on piston B, C , d provide same prerssure.