16: Equations

Question 1

Relationship of Current, Voltage and No. of coils in a primary and secondary coil
what is the ratio called
what does the minus sign signify

Answer 1

V₁ / V₂ = -N₁ / N₂ = -I₂ / I₁
Current is different!!!
1 = primary
2 = secondary
N1 / N2 = the turns ratio, number of turns in primary / number of turns in secondary
the alternating pd in the second coil is 180 degrees out of phase with the alternating pd across the primary coil

Question 2

Permeance =

Just for proportionality, calculations aren’t necessary

Answer 2

Permeance Λ = μA/L
where μ = permeability
A = cross-sectional area
L = Length

Question 3

flux linkage

Answer 3

NΦ

Question 4

emf induced in a rod moving through a uniform magnetic field

Answer 4

E  =  vLB
v = velocity
L = length
B = flux density

Question 5

units for flux density

Answer 5

Wb m^-2

(1 T tesla) = N A^-1 m^-1

Question 6

power generated by moving rod cutting through lines of flux

condition for this to happen

Answer 6

P = I(vLB)
P =power
I = current
v = velocity
L = length
B = flux density
rod must be moved perpendicular to the lines of flux

Question 7

equation to calc flux when its at an angle not 90 degrees

Answer 7

flux = BA cos theta

Question 8

how to calculate voltage using flux linkage

Answer 8

V (emf) = flux linkage / time