Question

state coulomb's law and write its expression

Answer 1

Coulomb’s Law In Vector Form

Let the position vectors of charges q1 and q2 be r1 and r2 respectively Fig.We denote force on q1 due to q2 by F12 and force on q2 due to q1by F21. The two point charges q1 and q2 have been numbered 1 and 2 for convenience and the vector leading from 1 to 2 is denoted by r21:



r21 = r2 – r1. In the same way, the vector leading from 2 to 1 is denoted by r12: r12 = r1 – r2 = – r21 .The magnitude of the vectors r21 andr12 is denoted by r21 and r12, respectively (r12 = r21). The direction of a vector is specified by a unit vector along the vector. To denote the direction from 1 to 2 (or from 2 to 1), we define the unit vectors:



Coulomb’s force law between two point charges q1 and q2 located at r1 and r2 is then expressed as



If q­1 and q2 are of the same sign (either both positive and both negative), F21 is along ˆr 21, which denotes repulsion, as it should be for like charges. If q1 and q2 are of opposite signs, F21 is along – ˆr 21(= ˆr 12), which denotes attraction, as expected for unlike charges.

Answer 2

Answer:

According to Coulomb's law of electrostatic force, the electrostatic force of attraction and repulsion is inversely proportional to the square of the distance between the charges and directly proportional to the product of the charges.

Expression: F∝q1×q2⇒F∝1r2

Explanation:

Coulomb's law states that the electrical force of attraction or repulsion between two stationary charges is inversely proportional to the square of the distance between them and directly proportional to the product of the magnitude of their charges. Scalar and vector forms can both be used to define Coulomb's law formula. Where r is the scalar measure of the gap between the charges, q1, q2 are the signed magnitudes of the charges, and ke is the Coulomb's Law constant (ke ≈ 8.99 × 109 N⋅m2⋅C−2). The force of attraction or repulsion between two point charges is determined by Coulomb's Law. The strength of the repelling or attracting force between two point charges, q1 and q2, is given by the formula F = k|q when the distance between them is r.

Thus, the amount of power carried by a one-ampere current in a second is known as a coulomb.