why do we use negative feedback in Amplifiers?

I need answer within 20 minutes please please with my best wishes

It was correct to talk about a virtual ground for the inverting amplifier. why isn’t it correct to refer to a virtual ground for the noninverting amplifier? 

How do you add the gains of a two stage amplifier?

Explain how an inverting amplifier differs from a noninverting amplifier.

6. For common-source small-signal FETS, the output voltage is 180° phase shifted with respect to the Q 7. The operating cycle of a Class A amplifier is Q 8. The maximum efficiency of a Class B amplifier is Q 9. In analyzing op-amps, when the non-inverting input pin is at ground and the inverting input pin is also at 0 V for an AC signal, the technique is called as Q 10. is an op-amp application circuit which is useful in low pass filter circuits.

A differential amplifier is characterised by a common-mode gain, A cm from figure 2. Determine the CMRR of the amplifier. Round your answer to one decimal place and do not type any letters in the answer box. Your answer must be purely numerical! Click here for Figure 1 Figure 1 Common-mode output voltage, vocm (V) 4 2 0 -2 -4 -6 -1 Vocm versus Vicm which may be derived from figure 1, and a differential gain, A,, which may be derived " 0 Common-mode input voltage, Vicm (V) 1

Compare inverting and non-inverting amplifier? in a table

What is operational amplifier? Please give details explanation.

What are circuits can used to design Class B amplifier ? explain the important features ? for each