E7G06 - Amateur Extra Class

E7G06 : What is the gain-bandwidth of an operational amplifier?
A The maximum frequency for a filter circuit using that type of amplifier
B The frequency at which the open-loop gain of the amplifier equals one
C The gain of the amplifier at a filters cutoff frequency
D The frequency at which the amplifiers offset voltage is zero
Correct Answer: The frequency at which the open-loop gain of the amplifier equals one