Capacitors: find the dielectric constant

AI Thread Summary
To find the dielectric constant of a parallel plate capacitor with a capacitance of 7.8 μF, an area of 1.5 m², and a plate separation of 1.3 x 10^-5 m, the formula C = (K(8.85E-12)A)/d is used. An attempt to calculate K resulted in a value of 1.02E11, but there was confusion regarding the algebra, particularly with the placement of parentheses. It was noted that the area and length were switched in the initial calculation, leading to an incorrect result. Correcting these errors is essential for accurately determining the dielectric constant. The discussion emphasizes the importance of careful algebraic manipulation in physics problems.
Alice7979
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Homework Statement


A parallel plate capacitor has a capacitance of 7.8 μF when filled with a dielectric. The area of each plate is 1.5 m^2 and the separation between the plates is 1.3 x 10-5 m. What is the dielectric constant of the dielectric?

Homework Equations


C= (K(8.85E-12)A)/d

The Attempt at a Solution


K= (1.5(7.8E-6 F))/((8.85E-12)(1.3E-5)
=1.02E11
 
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Alice7979 said:

Homework Statement


A parallel plate capacitor has a capacitance of 7.8 μF when filled with a dielectric. The area of each plate is 1.5 m^2 and the separation between the plates is 1.3 x 10-5 m. What is the dielectric constant of the dielectric?

Homework Equations


C= (K(8.85E-12)A)/d

The Attempt at a Solution


K= (1.5(7.8E-6 F))/((8.85E-12)(1.3E-5)
=1.02E11

Your last expression is unclear because the parentheses do not work (I am assuming you forgot a closing parenthesis at the very end). Double check your algebra, it looks like you end up multiplying the capacitance by the area in finding K, which cannot be right.
 
Alice7979 said:

Homework Statement


A parallel plate capacitor has a capacitance of 7.8 μF when filled with a dielectric. The area of each plate is 1.5 m^2 and the separation between the plates is 1.3 x 10-5 m. What is the dielectric constant of the dielectric?

Homework Equations


C= (K(8.85E-12)A)/d

The Attempt at a Solution


K= (1.5(7.8E-6 F))/((8.85E-12)(1.3E-5)
=1.02E11

I had the area and length switched, thank you
 
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