* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Chapter 22
Survey
Document related concepts
Introduction to gauge theory wikipedia , lookup
Magnetic monopole wikipedia , lookup
History of electromagnetic theory wikipedia , lookup
Anti-gravity wikipedia , lookup
History of quantum field theory wikipedia , lookup
Electromagnetism wikipedia , lookup
Speed of gravity wikipedia , lookup
Circular dichroism wikipedia , lookup
Maxwell's equations wikipedia , lookup
Aharonov–Bohm effect wikipedia , lookup
Lorentz force wikipedia , lookup
Field (physics) wikipedia , lookup
Transcript
CHAPTER-22 Electric Field 1 Ch 22-2 Electric Field Field: Region of space characterized by a physical property Scalar physical property- scalar field; vector physical property- vector field The Electric Field characteristics: Exerts force on a positive test charge Electric field is due to a charge and surrounds it Direction of E( given by arrow head): away from a positive charge and towards a negative charge 2 Ch 22-3 Electric Field Lines Space around charge filled with lines of force or electric field lines Direction of E-field lines or direction of the tangent to a curved field line gives the direction of E at that point. Number of E-field lines per unit area , measured in a planeto the lines, is proportional to the magnitude of E. Closer lines, larger E and farther the lines, the weaker is E field Parallel E field lines means uniform E-field 3 Ch 22-4 Electric Field Due to a Point Charge Electric Field due to a point charge E qo P E=F/q0=kq2/r2 E-field due to sum of Charges: Enet=Ei =E1+E2+E3+…. q r 4 Ch 22-4 Electric Field Due to a Point Charge Field between three charges: Zero Net Field location: For opposite charges , it is on the sides of the charges and nearer to weaker charge For similar charges , it is between the charges and nearer to weaker charge 5 Ch 22-5 Electric Field Due to a Electric Dipole Electric Field Due to a Electric Dipole Ed=2kqd/z3= (1/20) p/z3 where p is electric dipole moment given by: p=qd direction of p is taken from negative end to positive end of dipole 6 Ch 22-8 A Point Charge in an Electric Field The electrostatic force F on a charge q in an external field E is in the direction of E for positive charge and in opposite direction for negative charge 7 Ch 22-9 A Dipole in an Electric Field Net torque on the dipole = p xE =pEsin Negative torque for clockwise rotation =- pEsin Positive torque for counterclockwise rotation =pEsin Potential Energy U of a Dipole (U90=0) F+ Fx-axis U=-W=- 90d= 90pEsin d U=-p Ecos = -p.E Umin=-pE (=0); Umax=+pE(=180); W=-U=-(Uf-Ui) 8 Suggested problems Chapter 22 9