In the given circuit if the voltage inputs V- and V+ are to be Amplified by the same Amplification factor, the value of 'R' should be

A change in the value of the Emitter resistance (R_e in a difference Amplifier.

An op-Amp is used as a zero-crossing detector. If maximum output available from the Op-Amp is $$ \pm 12\,\,{V_{p - p}}$$ and the slew rate of the Op-Amp is 12 $$V/\mu $$ sec then the maximum frequency of the input signal that can be applied without causing a reduction in the P-P output is _____

To obtain very high input and output impedances in a feedback Amplifier, the mostly used is