Question #71201
hi is it possible to calculate the force between two parallel plates?
Expert's answer
If the plates carry equal but opposite charges, the force of attraction, which is conservative, is given by
F=-∂W/∂x.
But
W=q^2/2C.
For the parallel plate capacitor,
C=(ε_0 S)/x,
where x is the distance of separation. So
F=-d/dx ((q^2 x)/(2ε_0 S))=-q^2/(2ε_0 S)=-(ε_0 SU^2)/(2d^2 ),
where we have put x=d and q=CU.
Answer. F=-(ε_0 SU^2)/(2d^2 ).
F=-∂W/∂x.
But
W=q^2/2C.
For the parallel plate capacitor,
C=(ε_0 S)/x,
where x is the distance of separation. So
F=-d/dx ((q^2 x)/(2ε_0 S))=-q^2/(2ε_0 S)=-(ε_0 SU^2)/(2d^2 ),
where we have put x=d and q=CU.
Answer. F=-(ε_0 SU^2)/(2d^2 ).
Learn more about our help with Assignments: Electric Circuits
Comments