The question tells us that the voltage gain divided by the current amplification factor ( β ) equals 4. We know that the formula for voltage gain in a common emitter amplifier is AV=‌
β×RC
RB
, where RC is collector resistance and RB is base resistance. So if we divide AV by β, we get: ‌
AV
β
=‌
‌
β×RC
RB
β
This simplifies to: ‌
RC
RB
The question gives ‌
AV
β
=4, so: ‌
RC
RB
=4 This means the ratio of collector resistance to base resistance is 4:1.
