chapter three faraday experiment and lenz rule Flashcards
faraday experment
draw page 114
- plunge and remove a magnet in and out a solenoid of insulated copper wire and its terminals are connected to a middle zero sensitive galvnometer
- observation
- the pointer of the galvanometer is deflected MOMENTARILY in a certain direction when the magnet is plunged while it deflect in oppiste direction when the magnet is removed
faradays conclusion
the direction of the induced E.M.F is in a conductor depends on
the relative motion between a conductor and magnetic filed
the motion causes what
motion causes increases or decreases in the magnetic flux lines linked with it
what is the value of the induced E.M.F in a conductor depends on
the rate by which the conductor cuts the magnetic flux lines with it and number of turns
diff weber
it is the magnetic flux which if passes normally by on turn , and vanishes in one sec produces between the two terminals of the turn and induced E.M.F that equels 1 volt
the momentary deflection of the sensitive galvcanometer increases if the coil is wounded on soft iron cylinder GR
becaise soft iron has high magnjetic permeability so it will concentrate the magnetic flux denisty
diff faradays law in electromagnetic induction
the induced electrommotive force is directly proportional to the rate by which the conductor cuts the lines of the magnetic flux linked with , and directly proportional to the number of turns of the coil that cut the magnetic flux
–ve added in the faraday relation according to
lenz rule
diff lenz rule and use
uses; to determine the direction of the induced current in a coil
when ever E.M.F is induced the induced current must be in direction such as to resist the change in the magnetic flux producing
what will happen if the magnet plungd into coil
- electric current will be induced as a result of the increases in magnetic filed that link with the coil
- the induced electric current will flow in a direction to produce induced magnetic filed opposes the inducing magnetic filed , and that will resist the increase of the inducing magnetic filed linked with it
__NOTE ; N eln7yt el magnet بتقابل N
اخاصمك اه
w
hat will happen if the magnet pulled out from coil
- electric current will be induced as a result of the decreases in magnetic filed that link with coil
- the indused electric current will flow in direction to produced induced magnetic filed in same direction of inducing magnetic filed , that will resist the decrease in inducing magnetic filed link with it
NOTE ; N elni7it el magnet بيقبلها S
اسيبك لا
what is the average of when the coil makes 1\4 revolution during interval of time ( delta t ) = T\4
the magnetic flux passes through the coil vaneshes
Eind = –N x Døm \ D t
= –N x øm2 – øm1 \ D t
= –N x 0– BA \ T\4
= – N x 4BA \ T
= ABN4F
what is the average of when the coil makes 1\2 revolution during interval of time ( delta t ) = T\2
the magnetic flux passes through the coil reverced
Eind = –N x Døm \ D t
= –N x øm2 – øm1 \ D t
= –N x –BA – BA \ T\2
= –N x –2BA \ T\2
= – N x 4BA \ T
= ABN4F
what is the average when the coil make complete revolution Dt = 1
NO change in the magnetic flux passes through the coil
Eind = –N x Døm \ Dt
= –N x øm2 – øm1 \Dt
= –N x BA x BA \ Dt
the average in 1\4 and 1\2 revolution are equel GR
the magnetic flux passes through the coil vaneshes
Eind = –N x Døm \ D t
= –N x øm2 – øm1 \ D t
= –N x 0– BA \ T\4
= – N x 4BA \ T
= ABN4F
and
the magnetic flux passes through the coil reverced
Eind = –N x Døm \ D t
= –N x øm2 – øm1 \ D t
= –N x –BA – BA \ T\2
= –N x –2BA \ T\2
= – N x 4BA \ T
= ABN4F
