Question 39846
<pre><font size = 5><b>Vp over VS = Np over Ns this 
transposes to Vs= Vp x Ns over Np

Let's do it with plain letters first.

 A     C
——— = ———
 B     D

Multiply both sides by B*D/1

B*D    A     B*D    C
——— * ——— =  ——— * ———
 1     B      1     D

Cancel the B's on the left and the D's on the right


<s>B</s>*D    A     B*<s>D</s>    C
——— * ——— =  ——— * ———
 1     <s>B</s>      1     <s>D</s>


D*A = B*C

Divide both sides by C

D*A   B*C
——— = ———
 C     C

Cancel the C's on the right:

D*A   B*<s>C</s>
——— = ———
 C     <s>C</s>

D*A   
——— = B 
 C     

or if you prefer

    D*A   
B = ———  
     C

Now put Vp where I have A, VS where I have B,
Np where I have C, and Ns where I have D.  

Edwin</pre>