In a $CE$-transistor feedback oscillator circuit,the phase difference between input and output signal is

To use a transistor as an amplifier,which of the following conditions must be satisfied?

In a transistor amplifier,the voltage gain is

In a transistor amplifier,the base-emitter junction is forward-biased and the collector-emitter junction is reverse-biased. The current gain is defined as:

In the given common-emitter circuit, an $npn$ transistor with $\beta = 100$ is connected. What is the output voltage of the amplifier?

Given below are two statements:
Statement $I :$ $PN$ junction diodes can be used to function as a transistor,simply by connecting two diodes back-to-back,which acts as the base terminal.
Statement $II :$ In the study of transistors,the amplification factor $\beta$ indicates the ratio of the collector current to the base current.
In the light of the above statements,choose the correct answer from the options given below: