Measurement of the Gain Bandwidth-Product of the Op-amp:

The equivalence of Figure (b) recommend an interesting way of measuring the gain bandwidth product of an op-amp. By connecting an inductor L in series with this circuit a series resonant circuit is acquired for which the resonant frequency given by

f₀  = 1/ [2π (L / A₀ ω_p R_p )]^(1/2)

may be easily determined experimentally. A₀ ω_p may then be determined because R, L and f₀ are known.