Question 991290
VO / VI = NO / NI


VO = voltage out
VI = voltage in
NO = number of coils out
NI = number of coils in


VI = 120 volts
VO = 18 volts


NI = 180
NO = x


x = the number of coils out.


you want to solve for x.


VO / VI = NO / NI becomes 18 / 120 = x / 180


cross multiply to get 18 * 180 = 120 * x


divide both sides of the equation by 120 to get 18 * 180 / 120 = x


solve for x to get x = 27.


number of coils out needs to be equal to 27.


you get:


VI = 120
VO = 18
NI = 180
NO = 27


VO / VI = NO / NI becomes 18 / 120 = 27 / 180


simplify to get .15 = .15 which is true, confirming the solution is correct.


the solution is that the number of coils on the output circuit are equal to 27.