How to Find Electric Flux

Charge differs across curved surfaces.

Electric flux measures the density of electric field lines proceeding from a surface. The magnitude of a surface's electric flux depends on the strength of the field, the size of the surface and the angle between the surface and the field. Gauss' law uses integral calculus to derive a formula for electric flux using just the enclosed electrical charge and the electric permittivity of free space. This latter constant derives from the speed of light and the magnetic permeability of free space.

Instructions

1. Square the speed of light, which is 3.0 --- 10^8: (3.0 --- 10^8)² = 9.0 --- 10^16.

2. Multiply this answer by the magnetic permeability of free space, which is 1.26 --- 10^-6: (9.0 --- 10^16) --- (1.26 --- 10^-6) = 1.13 --- 10^11.

3. Divide 1 by this answer: 1 ÷ (1.13 --- 10^11) = 8.84 --- 10^-12.

4. Divide the charge that the surface encloses by this answer. If, for instance, it encloses a charge of 1.6 --- 10^-5 Coulombs: (8.84 --- 10^-12) ÷ (1.6 --- 10^-5) = 5.53 --- 10^-7. This is the strength of the electric flux, measured in volt-meters.

References

• Boston University: Electric Field; 1999
• Georgia State University: Gauss's Law; R. Dave
• Tennessee Tech University: Gauss's Law; David P. Murdock

Resources

• The University of Tennessee: Gauss' Law
• Davidson College: Electric Flux