PHYS 270 – SUPPL. #6 DENNIS PAPADOPOULOS FEBRUARY 11, 2010

Hydro-Electric Station Watch movie at

Hydroelectric Power From last lecture

TETHERED SATELLITE SYSTEM EMF=vlB= (8 km/sec) (20 km)(.3 x10 -4 T)=4.8 kV R= 4.8 kV/1A=4800 OhmP=I(EMF)=4.8 kW

Falling magnet slows down as it approaches a copper ring immersed in liquid Nitrogen Why ? and what is the use of liquid Nitrogen ?

Falling magnet slows down as it approaches a copper ring immersed in liquid hydrogen Insert movie for falling magnet

MAGNETIC FLUX CONVENTIONS  cos  UNIFORM B NON-UNIFORM B

N number of loops in a coil What about the minus sign ?

LENZ’s LAW APPLICATION

Falling magnet – changes Magnitude of B Copper Ring Falling towards a dipole magnet

Will be discussed in detail during recitation

EDDY CURRENTS Induced current causes force

LOOP CURRENT BY TEMPORAL FLUX CHANGE –LENZ’s LAW

FARADAY’s LAW

GENERATORS – TRANSFORMERS- DETECTORS

MAGNETIC FLUX  IS THE ANGLE THE AXIS OF THE LOOP MAKES WITH THE DIRECTION OF B