Question

The distance between the plates of a plane capacitor was increased in 3 times. In how many times has the charge, the voltage between the plates and the field strength changed, if the capacitor: a) was cut off from the voltage source; b) remained connected to the source of constant tension?

Answer 1

a) If the capacitor is disconnected from the voltage source, the charge on it can not be changed under any circumstances. So everything remains the same.
b) C = εoε*(S/d)
If the distance increased, the capacity decreased 3-fold. C = Q/U. If the capacity diminished, the charge reduced 3-fold. The electric current in various media.