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Flashcards in Electromagnetic Induction Deck (18):
1

Faradays Laws of EMI

E= -dδ/dt;
E= emf generated
δ= Magnetic flux

2

Magnetic flux δ=?

δ=NB.A
; A=Area
B= Magnetic field
δ= Magnetic Flux

3

State Lenz's Law

EMF generated opposes change in flux

4

Motional EMF E=?

E= Bvl= Bωl²/2=BAf
; f= frequency
l= length of conductor
ω= angular frequency

5

Induced current I=?

I= I₀ sin ωt

6

Coefficient of self induction δ=?

δ=LI
E=-L dI/dt
; L= coefficient of self induction

7

Self induction L of long solenoid =?

L= μ₀N²A/l= μ₀ n²Αl
; N= No of turns
n= Turn density
l=length of coil
A= Area of cross section of coil

8

Self inductance L of toroid =?

L= μ₀N²A/2πr
; A= Area of cross section of toroid

9

Energy E stored in an inductor =?

E= 1/2 Li^
; L = Inductance
I= Current

10

Coefficient of mutual inductance δ=?

δ=MI
E=-M dI/dt
; M = coefficient of mutual inductance

11

In EMI , coefficient of coupling K=?

K= M/√L1L2
;L1,L2= Mutual inductance of respective coils
K= coefficient of coupling

12

Mutual inductance M of long coaxial solenoid =?

M= μ₀N1N2A/l
;N1,N2= No of turns on respective solenoids
l= length of solenoid
μ₀= permittivity of free space

13

Grouping of coils in series of M=0

L=L1+L2
; L= Self inductance

14

Grouping of coils in series if current in coils is in same direction

L=L1+L2+2M

15

Grouping of coils in series if current is in opposite direction

L=L1+L2-2M

16

Grouping of coils in parallel if current is in same direction in coils

L=L1L2-M^/L1+L2+2M

17

Grouping of coils in parallel if current in coils is in opposite direction

L=L1L2-M^/L1+L2-2M

18

Eddy current i= ?

i= -e/R
;e= induced emf
i= eddy current