How does EM induction and the motor effect work?

Question

anonymous · Answer

(1) How is the Lorentz force law derived?
(2) For the motor effect, is a fair explanation that the moving electrons experience a force downwards due to a magnetic force, and push the wire down with them due to EM repulsion between them and the metal atoms?
(3) For EM induction, why is there a dB/dt term if there is not in the Lorentz force law? I am confused intuitively about it; I understand what happens, but not why above the level of rote.

masumanwar · Answer

induced emf was first suggested by Michel Faraday and by applying circuit for close loop using inductor and applying dc or ac voltage we can measure induced emf

shamim · Answer

lorentz force law is  $$F=qE+q(v  \times B)$$

shamim · Answer

here  q= charge
         F=force and its a vector
         E=electric field and its a vector
         v=velocity of charge q and its a vector
        B= magnetic field and its vector

shamim · Answer

if in any place both electric field E and magnetic field B present then this lorentz force law will b applied

shamim · Answer

Lorentz force law can b writen as$$F=q(E+v \times B)$$

shamim · Answer

ur question 2 is not clear to me

shamim · Answer

now i wanna talk abt ur question 3

anonymous · Answer

That's not the derivation, it's just a statement of the law.

shamim · Answer

ya