Meter Bridge or Slide Wire Bridge—

it is an arrangement based on the principle of Wheatstone Bridge used to measure an unknown resistance.

Construction—

Wheatstone Bridge—

It is arrangement of four resistances used to determine one unknown resistance with the help of remaining three resistances.

In this arrangement we arrange four resistances P, Q, R and S as shown in figure.

On applying Kirchhoff’s Law

Coulomb's law in electrostatics--

It states that two point charges attract or repel each other with a force which is directly proportional to the product of the magnitudes of charges and inversely proportional to the square of the distance between them.

Properties of charges

1. Conserved
2. Additive
3. Quantized

1.Conserved

Charge is conserved in nature means it neither be created Nor be destroyed. It is transferred from one body to other body.

2. Additive

The total electric charge on an object is equal to the algebraic sum of all the electric charges distributed on the different parts of that object.

           q=q₁+q₂+q₃+.......