The thinnest part of a transistor is . . . . . .

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

In a silicon transistor,a change of $7.89 \, mA$ 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 an equivalent change in the collector current (in $mA$)?

In the transistor circuit shown,assume that the voltage drop between the base and the emitter is $0.5\ V$. What will be the ratio of the voltage across resistances $R_2$ and $R_1$ in order to make this circuit function as a source of constant current,$I = 1\ mA$?

Which of these is a unipolar transistor?

$A$ transistor is used as an amplifier in a common-base configuration. The load resistance is $5 \text{ k}\Omega$, the current gain is $0.98$, and the input resistance is $70 \Omega$. The voltage gain and power gain are, respectively: