Why Does Voltage Drop When a Dielectric Is Inserted in a Capacitor?

  • Thread starter Thread starter Monts
  • Start date Start date
  • Tags Tags
    Dielectric parts
Click For Summary
SUMMARY

The discussion centers on the phenomenon of voltage drop in a capacitor when a dielectric material is inserted. A circular metallic plate capacitor, initially charged to 10V, experiences a voltage drop to 4V upon inserting a dry plastic racket filled with water. This drop occurs due to the dielectric properties of water, which has a high dielectric constant, affecting the electric field between the plates. When the water is removed, the voltage returns to 10V, indicating that the dielectric's presence significantly alters the capacitor's behavior.

PREREQUISITES
  • Understanding of capacitor fundamentals, including capacitance and voltage.
  • Knowledge of dielectric materials and their properties.
  • Familiarity with the concept of electric fields and charge distribution.
  • Basic physics equations related to capacitance, particularly with dielectrics.
NEXT STEPS
  • Research the formula for capacitance with dielectric constant ε, specifically C = εA/d.
  • Investigate the dielectric constant values for various materials, focusing on water and air.
  • Explore the effects of different dielectric materials on capacitor performance.
  • Study the relationship between electric field strength and voltage in capacitors.
USEFUL FOR

Students in physics courses, educators teaching capacitor theory, and anyone interested in the practical applications of dielectrics in electrical engineering.

Monts
Messages
2
Reaction score
0

Homework Statement



This was done on my Physics II class, ans the Professor has'nt want to explain it to usA 2 Circular Metallic Plate Capacitor, maybe of a diameter of 15cm, was connected to a constant sourch of DC voltage until it was charge to 10Volt, after this the source was DISCONNECTED from the Capacitor, and of course the voltage on it remained at 10V

Then, the professor took a DRY plastic racket with 500ml of water INSIDE, and puts it between the plates, leaving no space between them, it was very precise, the plates where adjusted to the specific width of the racket. By doing this the voltage went down to 4V

And then, he takes the racket out the Capacitor, bringing the voltage back to 10V, and empties all the water and closes the little overture. After this he put the racket back between the plates and the voltage comes down to 4volts AGAIN.

Homework Equations



Why does the change of the Dielectric makes no difference?

The Attempt at a Solution



The water leaving the racket gives up a large quantity of ions, making the air so conductive to the field as it was before
 
Physics news on Phys.org
What is the formula for capacitance with dielectric constant ε?

What is ε for water and for air?
 

Similar threads

Electric field between capacitor plates when a dielectric slab is inserted
  • · Replies 14 ·
Replies
14
Views
3K
Which of the two dielectrics breaks down first?
  • · Replies 2 ·
Replies
2
Views
2K
Undergrad A change in the dielectric constant changes the current or voltage?
  • · Replies 12 ·
Replies
12
Views
4K
Undergrad Voltage drop across a capacitor and resistor in series
  • · Replies 19 ·
Replies
19
Views
5K
Undergrad Work done when Inserting a Dielectric between Capacitor Plates
  • · Replies 3 ·
Replies
3
Views
6K
Capacitor and Dielectric: Charge, Arrangement, and Extraction Calculations
  • · Replies 6 ·
Replies
6
Views
2K
How Does Dielectric Insertion Affect Capacitor Behavior?
  • · Replies 5 ·
Replies
5
Views
2K
Which Equations Apply When a Dielectric is Inserted into a Live Capacitor?
  • · Replies 7 ·
Replies
7
Views
2K
Why Does a Dielectric Slab Experience Force When Fully Inserted in a Capacitor?
  • · Replies 3 ·
Replies
3
Views
6K
How Does Inserting a Dielectric Affect a Charged Capacitor?
  • · Replies 10 ·
Replies
10
Views
3K