In an unloaded transformer, the fluxes limiting the primary

In an unloaded transformer, the fluxes limiting the primary and secondary are 25 mwb and 15 mwb. The coefficient of coupling—

As we know that

e = – N	dφ	, we can say
	dt

N₁	1
	φ₁

or		N₁	=	φ₂
		N₂		φ₁

or		N₁	=	15	= 3: 5
		N₂		25