Chapter 11 Magnetic Fields: IV Motional electromotance a faraday induction Law forVx B Fields a Lenz' law Faraday induction Law for time- Dependent b Flux Linkage E in terms of∨andA
Chapter 11 Magnetic Fields:IV ◼ Motional Electromtance ◼ Faraday Induction Law for v x B Fields ◼ Lenz’ Law ◼ Faraday Induction Law for TimeDependenct B ◼ Flux Linkage ◼ E in Terms of V and A
In this chapter we are with two phenomena 1) The Lorentz force Qv x b on the charge carriers inside a moving conductor 2)If a magnetic field is time-dependent, then there appears an electric field -aA(t/at
11.1 Motional electromotance Consider a conductor moving at a velocity v in a magnetic field The conduction electrons inside the conductor also move with v Then we know that the conduction electrons drifts driven by the lorentz force -ev x B If the conductor forms a closed circuit c, then the electrons move, forming a current in the circuit as if there were a battery supplying a voltage =f(v×B)
Remarks 1v is called the induced electromotance, or the motional electromotance. Its unit is volt 2 )V adds algebraically to the voltages of other sources that may be present in the circuit
11.2 The Faraday Induction Law for v B Fields The induced electromotance can be written as =(v×B)·dl=-B·(v×dl, where we have used the formul (A×B)C=-B·(AxC), which is true for any vectors a, b, and c