Question

2 amplifiers with a gain of 12 and 15 are connected in series.the output voltage is 3.6v. what is the input voltage

Answer 1

I assume that the two amplifiers are voltage amplifiers.

WHen they are connected in series the gains multiply.  So combined gain of the two ampliifiers is = 12 * 15 = 180

Output voltage = 3. 6 Volts  = overall gain  * input voltage
Input voltage = 3. 6  Volts / 180  = 0.02 Volts

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