Class 12th Physics-Electric Charges and Fields – Properties of Charges – like and Unlike part-4.

Class 12th Physics-Electric Charges and Fields – Properties of Charges – like and Unlike part-4.

Class 12 Physics – Electric Charges and Fields

Properties of Electric Charges (Like and Unlike Charges) – Part 4

Electric charge is a fundamental property of matter responsible for electromagnetic interactions. Here, we discuss the like and unlike charges in detail.

1. Types of Electric Charges

There are two types of electric charges:

• Positive Charge (+) – Carried by protons.
• Negative Charge (-) – Carried by electrons.

2. Like and Unlike Charges

Like Charges Repel Each Other:

• Two positive (+, +) or two negative (-, -) charges push away from each other.
• This happens due to Coulomb’s Law, where similar charges exert a repulsive force.

Unlike Charges Attract Each Other:

• A positive (+) charge and a negative (-) charge pull toward each other.
• This attraction is also governed by Coulomb’s Law.

Example:

• Like Charges: Two electrons repel each other.
• Unlike Charges: A proton and an electron attract each other.

3. Coulomb’s Law (Mathematical Representation)

The force between two point charges q₁ and q₂ is given by:

F=k⋅∣q1q2∣r2F = \frac{k \cdot |q₁ q₂|}{r^2}F=r2k⋅∣q1​q2​∣​

where:

• F = Electrostatic force
• k = Coulomb’s constant (9 × 10⁹ Nm²/C²)
• q₁, q₂ = Magnitudes of the charges
• r = Distance between the charges

 If q₁ and q₂ have the same sign, F is positive (repulsion).
 If q₁ and q₂ have opposite signs, F is negative (attraction).

4. Applications of Like and Unlike Charges

Electrostatic Precipitators: Used in industries to remove dust particles using charge attraction.
Photocopiers and Laser Printers: Use charge distribution to print images.
Lightning: A result of charge accumulation and attraction between clouds and the ground.

Would you like a numerical example based on this concept?

Class 12th Physics-Electric Charges and Fields – Properties of Charges – like and Unlike part-4.