How Does Inserting a Dielectric Affect Voltage in an Uncharged Capacitor?

AI Thread Summary
Inserting a dielectric into an uncharged capacitor decreases the voltage because it reduces the net electric field between the conductors. The presence of the dielectric increases the capacitance while keeping the charge constant, leading to a lower voltage according to the formula V=Q/C. This phenomenon is also influenced by the dielectric's properties, specifically its polarization, which further contributes to the decrease in voltage. The discussion emphasizes the relationship between capacitance, charge, and voltage in the context of dielectrics. Understanding these principles is crucial for comprehending capacitor behavior in electrical circuits.
Gear300
Messages
1,209
Reaction score
9
For a capacitor not connected to a battery, why does the voltage decrease with the insertion of a dielectric. Would it be because the net electric field between the conductors is decreased?
 
Physics news on Phys.org
you just answered your own question. there is also less room for particles to lose potential over.
 
username2 said:
you just answered your own question. there is also less room for particles to lose potential over.

Gear300, your answer is a lot better than this one. Yes, the dielectric decreases the electric field. What do you mean "less room"?
 
alternative method :
Q=CV
V=Q/C

insert a dielectric , keeping the charge accumulated unchanged. the greater the dielectric(coefficient e), the greater the capacitance and the lower the voltage across

but why. it is related to the properties of dielectric ... and polarization makes the V decreases as well as ... that's another story
 
  • Like
Likes gracy
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'Calculation of Tensile Forces in Piston-Type Water-Lifting Devices at Elevated Locations'
Figure 1 Overall Structure Diagram Figure 2: Top view of the piston when it is cylindrical A circular opening is created at a height of 5 meters above the water surface. Inside this opening is a sleeve-type piston with a cross-sectional area of 1 square meter. The piston is pulled to the right at a constant speed. The pulling force is(Figure 2): F = ρshg = 1000 × 1 × 5 × 10 = 50,000 N. Figure 3: Modifying the structure to incorporate a fixed internal piston When I modify the piston...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top