The voltage across an air-filled parallel-plate capacitor is measured to be 125.

Question

The voltage across an air-filled parallel-plate capacitor is measured to be 125.0 V. When a dielectric is inserted and completely fills the space between the plates as in the figure below, the voltage drops to 36.8 V.

(a) What is the dielectric constant of the inserted material?


Can you identify the dielectric?
---Select--- paper nylon bakelite neoprene rubber teflon

(b) If the dielectric doesn't completely fill the space between the plates, what could you conclude about the voltage across the plates?

Explanation / Answer

(a)Q=CV

as Q is constant, C and V changes such that Q is constant. Now C increases when dielectric is inserted.

C --> C*k

V--> V/k

V(initial) =125V

V(dielectric) = V(initial)/k   

k= 3.39= dielectric constant

dielectric = nylon

(b) If the dielectric doesn't completely fill the space between the plates,voltage across plates will increase a bit more than when it completely fills as dielectric constant of air is less than 3.4(=1).

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.