Why Is My Calculation of the Dielectric Constant Incorrect?

[roro0505]

the answer i keep getting is wrong ... help?

Homework Statement

Two parallel plates of area 110 cm2 are given charges of equal magnitudes 9.6 × 10-7 C but opposite signs. The electric field within the dielectric material filling the space between the plates is 4.2 × 106 V/m.

(a) Calculate the dielectric constant of the material.
(b) Determine the magnitude of the charge induced on each dielectric surface.

Homework Equations

k=q/(E*A*epsilon_0)

q'=q(1-(1/k))

The Attempt at a Solution

k=q/(E*A*epsilon_0)
=9.6E-7/(4.2E6*110E-4*8.85E-12)
=2.3

q'=q(1-(1/k))
=9.6E-7(1-(1/2.3))
=5.4E-7

 

[Andrew Mason]

the answer i keep getting is wrong ... help?

Homework Statement

Two parallel plates of area 110 cm2 are given charges of equal magnitudes 9.6 × 10-7 C but opposite signs. The electric field within the dielectric material filling the space between the plates is 4.2 × 106 V/m.

(a) Calculate the dielectric constant of the material.
(b) Determine the magnitude of the charge induced on each dielectric surface.

It is not clear but I suspect that these are non-conducting plates, in which case Gauss' law is:

$$\oint E dA = E2A = \frac{Q}{k\epsilon_0}$$

AM

 

[m2003]

(a) The dielectric constant of the material is 2.3.
(b) The magnitude of the charge induced on each dielectric surface is 5.4 × 10-7 C.



It seems like your calculations are correct. However, if you are still getting the wrong answer, double check your units and make sure they are consistent throughout your calculations. Also, make sure you are using the correct value for the permittivity of free space, which is 8.85 × 10-12 C2/Nm2. If you are still having trouble, try asking your teacher or a classmate for help. Sometimes, a fresh perspective can help identify any mistakes. Keep practicing and don't get discouraged!