Coulombs law and electric field intensity
Coulombs law and electric field intensityElectric power transmission, X-ray machines, and lightning protection are associated with strong electric fields and will require a knowledge of electrostatics to understand and design suitable equipment. Take risks: if you win, you will be happy; if you lose you will be wise.PETER KREEFTelectrostaticsThe branch of science which deals with the phenomena associated with electricity at rest.
Charge-the total deficiency or excess of electrons in a body is known as its charge.Absolute and Relative Permittivity of a mediumEvery medium is supposed to possess these two permittivities.Vacuum or free space- reference medium for measuring relative permittivity.Has an absolute permittivity of 8.854 x 10-12 F/m
Absolute permittivity
Laws of electrostaticsFirst law : Like charges of electricity repel each other, whereas unlike charges attack.Second law: according to this law, the force exerted between two point charges is directly proportional to the product of their strength and inversely proportional to the square of the distace between them.Coulombs Law and field intensityCoulomb's law is an experimental law formulated in 1785 by the French colonel, Charles Augustin de CoulombIt deals with the force a point charge exerts on another point charge. By a point charge we mean a charge that is located on a body whose dimensions are much smaller than other relevant dimensions.
Coulombs LawCoulomb's law states that the force F between two point charges Q1 and Q2 is1. Along the line joining them2. Directly proportional to the product Q1Q2 of the charges3. Inversely proportional to the square of the distance R between them
Where k = proportionality constantQ1 and Q2 = in coulombs Distance R = in metersForce F = in Newtons (N)k= 1/ 4o
o=permittivity of free space
F= 9 x109 Q1Q2/ rR2 ExampleConsider a charge of 3 x 10-4 C at P (1,2,3) and a charge of -10-4 C at Q(2,0,5) in a vacuum. Solve for the force exerted on Q2 by Q1.Example 2A 2 mC (millicoulomb) positive charge is located in vacuum at P1 (3,-2,-4) and 5C(microcoulomb) negative charge is at P2(1,-4,2)
A. Find the vector force on the negative charge.
