Manju,

assume you want to amplify the audio band with a TL084. If you have a look at the datasheet, then you will realize, that at 30kHz the open loop gain of the TL084 is only 100. If you force the OPamp to provide a gain of 100, then you will not have any gain reserve to suppress distortion of OPamp by the help of feedback. So, you should have a gain reserve of at least 10 at any frequency of interest to allow the amplifier to work as an amplifier. In demanding applications this gain reserve can be even much higher.

So, if you have only DC to amplify, you can choose a higher gain per each OPamp stage, than when dealing with frequencies far away from DC: Increasing the bandwidth by a factor of 10 decreases the allowable gain by a factor of 10.

Kai Klaas