Download 20.3 Motional emf

Survey
yes no Was this document useful for you?
   Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Document related concepts

Electric machine wikipedia, lookup

History of geomagnetism wikipedia, lookup

Lorentz force wikipedia, lookup

Electromagnet wikipedia, lookup

Magnetic monopole wikipedia, lookup

Maxwell's equations wikipedia, lookup

Ferromagnetism wikipedia, lookup

Magnetoreception wikipedia, lookup

Skin effect wikipedia, lookup

Electromagnetism wikipedia, lookup

Neutron magnetic moment wikipedia, lookup

Mathematical descriptions of the electromagnetic field wikipedia, lookup

Eddy current wikipedia, lookup

Superconducting magnet wikipedia, lookup

Magnetohydrodynamics wikipedia, lookup

Force between magnets wikipedia, lookup

Faraday paradox wikipedia, lookup

Electricity wikipedia, lookup

Magnetism wikipedia, lookup

Magnetochemistry wikipedia, lookup

Electromotive force wikipedia, lookup

Multiferroics wikipedia, lookup

Ferrofluid wikipedia, lookup

Magnet wikipedia, lookup

Aurora wikipedia, lookup

Giant magnetoresistance wikipedia, lookup

Magnetotellurics wikipedia, lookup

Earth's magnetic field wikipedia, lookup

Magnetotactic bacteria wikipedia, lookup

Electromagnetic field wikipedia, lookup

Magnetometer wikipedia, lookup

Magnetic stripe card wikipedia, lookup

Edward Sabine wikipedia, lookup

Geomagnetic storm wikipedia, lookup

Magnetosphere of Saturn wikipedia, lookup

Transcript
20.3 Motional emf Consider the following situation. A conducting rod is moving to the right with a speed v in a magnetic field region directed into the page. The free electrons in the conductor are subjected to a magnetic force directed downwards and equals  =  So the electrons will move downwards leaving a positively charged region upwards and making a negatively charged region at the bottom. So an electric field directed downwards is induced When the magnetic force becomes equal to the electric force on a free electron, its motion stop and an induced emf is formed. From previous lessons ℰ =  Now ! = !  =  ℰ
=  
ℰ =   Δ =  This emf is called the motional emf because it is due to the motion of a conductor in a magnetic field Example: Consider a conducting rod moving along two conducting rails to the right with a speed v forming a closed loop. The system is placed in a magnetic field region as shown in the figure This is the same answer that we got for the motional emf as it must be. Moreover the current must flow CCW. If the resistance of the circuit is R, then