Consider two oppositely charged, isolated parallel plates separated by distance
ID: 1333607 • Letter: C
Question
Consider two oppositely charged, isolated parallel plates separated by distance D, with capacitance C, charge Q, and stored energy U. D is small compared to the dimensions of the plates. For each statement below, select "True" or "False". When D is doubled, U decreases. Because of energy conservation, inserting a dielectric leaves U unchanged. Because of charge conservation, inserting a dielectric leaves C unchanged. Increasing D, increases the E field. When D is doubled, C is halved. Inserting a dielectric increases Q. When D is halved, Q stays the same.Explanation / Answer
1)
Capacitance is inversely proportional to distance, thus, the increase in distance decreases capacitance and hence the energy. FALSE
2) Inserting a dielectric increases the capacitance by k times anddecreases the voltage by k times and U=0.5CV^2 .Thus, the energy decreases FALSE
3) FALSE
4) E=V/d TRUE
5)C=e_0A/d TRUE
6) TRUE
7)TRUE