ELECTRIC CHARGES AND FIELDS in One Shot - All Concepts & PYQs || NEET Physics Crash Course

About this Video

• Video Title: ELECTRIC CHARGES AND FIELDS in One Shot - All Concepts & PYQs || NEET Physics Crash Course
• Channel: Competition Wallah
• Speakers: Alka Pandey
• Duration: 7 hours, 34 minutes, 35 seconds

Introduction

This video is a NEET Physics crash course lecture covering the Class 12th chapter on Electric Charges and Fields. The speaker, Alka Pandey, aims to comprehensively explain all concepts and relevant past year questions (PYQs) within a single session, encouraging viewers to complete the lecture, solve all associated questions, and practice the provided practice sheet (available on the Physics Wallah app).

Key Takeaways

1. Electric Charge: Charge (q) is an intrinsic property of matter, with the SI unit being the Coulomb (C). Like charges repel, and unlike charges attract.
2. Conservation of Charge: The total charge of an isolated system remains constant; charge cannot be created or destroyed.
3. Quantization of Charge: Charge exists in discrete multiples of the fundamental charge (e), the charge of an electron (approximately 1.6 x 10^-19 C). Smaller charges exist (in quarks), but not independently.
4. Coulomb's Law: Describes the force between two point charges: F = kq₁q₂/r², where k is Coulomb's constant and r is the distance between the charges. The force is along the line joining the charges and is attractive for unlike charges and repulsive for like charges. For air or vacuum, k = 1/(4πε₀), where ε₀ is the permittivity of free space.
5. Electric Field: The region around a charge where a test charge experiences a force. Electric field intensity (E) is the force per unit charge: E = F/q. For a point charge, E = kq/r². The field is away from positive charges and toward negative charges. The electric field at the center of a symmetrical charge distribution is always zero.
6. Gauss's Law: The total electric flux through a closed surface is equal to (1/ε) times the net charge enclosed within the surface. The Gaussian surface should be symmetrical around the charge distribution, and it should not pass through any point charge.