# Is there back EMF in an induction motor?

I noticed that in deriving the equivalent circuit for an induction motor in the rotor component, that a "variable" resistance was introduced. This really confused me as I didn't understand how power was equivalent when they divided everything by slip in the derivation. Is there a back EMF being induced that forms the $$\frac{(1-s)}{s}R$$ portion of the circuit or something along those lines. Is this like an "induced resistance" or a voltage drop depending on slip that would form the component being converted to mechanical power?

Yes. The armature induces current in the rotor at $$\s\$$ times the line frequency. That current depends on slip, and the amount of coupling depends on slip, which is where the above relationship comes in.