# How many turns are in a coil?

#### Hussam Mj

Joined Oct 25, 2018
17
A) In a straight conductor, there is a current of 3 A. Find the field strength at a distance of 0.48 cm from the conductor.
b) The conductor is wrapped around a square stainless steel core (μr = 2410) with square cross-section, outer length is 20 cm and inner length is 16 cm. The field strength of the coil turns out to be the same
as in task a). The current in the coil is measured at 1.482 A. How many turns have the coil.
I solved question A but I am stuck at question B.
Any guidance?

#### shortbus

Joined Sep 30, 2009
9,766
Trick question? One of the values of the core is missing, the thickness.

#### Hussam Mj

Joined Oct 25, 2018
17
I applied this formula H=I.N/L.
where I the current
N number of turns
L the length of the coil.
H the field strength from question A. so we get
N=H.L/I
but I am not sure if this correct way to solve question B.

#### wayneh

Joined Sep 9, 2010
17,189
Trick question? One of the values of the core is missing, the thickness.
Square cross section.

#### wayneh

Joined Sep 9, 2010
17,189
I applied this formula H=I.N/L.
where I the current
N number of turns
L the length of the coil.
H the field strength from question A. so we get
N=H.L/I
but I am not sure if this correct way to solve question B.
The field in the steel depends on the permeability.

#### Alec_t

Joined Sep 17, 2013
13,237
The permeability values in the question and on the drawing don't match.

#### shortbus

Joined Sep 30, 2009
9,766
Square cross section.
That's why I said trick question. The square cross section, to my knowledge means the leg the winding is on.