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Flashcards in Electromagnetic Induction Deck (18)
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1
Q

Faradays Laws of EMI

A
E= -dδ/dt; 
E= emf generated 
δ= Magnetic flux
2
Q

Magnetic flux δ=?

A

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

3
Q

State Lenz’s Law

A

EMF generated opposes change in flux

4
Q

Motional EMF E=?

A

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

5
Q

Induced current I=?

A

I= I₀ sin ωt

6
Q

Coefficient of self induction δ=?

A

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

7
Q

Self induction L of long solenoid =?

A
L= μ₀N²A/l= μ₀ n²Αl
; N= No of turns 
n= Turn density 
l=length of coil 
A= Area of cross section of coil
8
Q

Self inductance L of toroid =?

A

L= μ₀N²A/2πr

; A= Area of cross section of toroid

9
Q

Energy E stored in an inductor =?

A

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

10
Q

Coefficient of mutual inductance δ=?

A

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

11
Q

In EMI , coefficient of coupling K=?

A
K= M/√L1L2
;L1,L2= Mutual inductance of respective coils 
K= coefficient of coupling
12
Q

Mutual inductance M of long coaxial solenoid =?

A
M= μ₀N1N2A/l
;N1,N2= No of turns on respective solenoids 
l= length of solenoid 
μ₀= permittivity of free space
13
Q

Grouping of coils in series of M=0

A

L=L1+L2

; L= Self inductance

14
Q

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

A

L=L1+L2+2M

15
Q

Grouping of coils in series if current is in opposite direction

A

L=L1+L2-2M

16
Q

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

A

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

17
Q

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

A

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

18
Q

Eddy current i= ?

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