The transfer characteristic curve of a transistor,having input and output resistance $100\,\Omega$ and $100\,k\Omega$ respectively,is shown in the figure. The voltage and power gain are respectively:

$A$ change of $0.04 \ V$ takes place between the base and the emitter when an input signal is connected to the common emitter transistor amplifier. As a result,a $20 \ \mu A$ change takes place in the base current and a change of $2 \ mA$ takes place in the collector current. The input resistance and $AC$ current gain are:

What is the basic constitutional unit in the electronic circuit?

In a $CE$ transistor, a change of $8.0 \,mA$ in the emitter current produces a change of $7.8 \,mA$ in the collector current. What change in the base current is necessary to produce the same change in the collector current (in $\mu A$)?

Three amplifiers,each having a voltage gain of $10$,are connected in series. The resultant gain would be

For transistor action:
$(1)$ Base,emitter and collector regions should have similar size and doping concentrations.
$(2)$ The base region must be very thin and lightly doped.
$(3)$ The emitter-base junction is forward biased and base-collector junction is reverse biased.
$(4)$ Both the emitter-base junction as well as the base-collector junction are forward biased.
Which one of the following pairs of statements is correct?