In a full wave rectifier circuit operating from $$50$$ $$Hz$$ mains frequency, the fundamental frequency in the ripple would be

In a common base amplifier, the phase difference between the input signal voltage and output voltage is

When $$npn$$ transistor is used as an amplifer

For a transistor amplifier in common emitter configuration for load impedance of $$1k\,\Omega $$ $$\left( {{h_{fe}} = 50} \right.$$ and $$\left. {{h_{oe}} = 25} \right)$$ the current gain is