What is the total inductance when two coils of 60 and 80 microhenries are connected in series without mutual coupling?

When two inductors are connected in series without mutual coupling, the total inductance is simply the sum of the individual inductances. This is because there is no magnetic interaction between the coils that would affect their overall inductance.

In this case, you have one coil with an inductance of 60 microhenries and another with an inductance of 80 microhenries. To find the total inductance, you add these two values together:

Total inductance = Inductance of coil 1 + Inductance of coil 2

Total inductance = 60 microhenries + 80 microhenries

Total inductance = 140 microhenries

This calculation shows that the correct answer is indeed 140 microhenries, as it is the sum of the two given inductances.