An $n-p-n$ transistor is biased to work as an amplifier. Which of the following statements is $NOT$ correct?

In an $n-p-n$ transistor circuit,the collector current is $10 \, mA$. If $90 \%$ of the electrons reach the collector,then the emitter current will be:

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

$A$ transistor is connected in common emitter $(CE)$ configuration. The collector supply is $8\ V$ and the voltage drop across a resistor of $800\,\Omega$ in the collector circuit is $0.5\ V$. If the current gain factor $\alpha$ is $0.96$,find the base current in $\mu A$.

$A$ transistor is used in an amplifier circuit in common emitter mode. If the base current changes by $100 \,\mu A$, it brings a change of $10 \,mA$ in collector current. If the load resistance is $2 \,k \Omega$ and input resistance is $1 \,k \Omega$, the value of power gain is $x \times 10^{4}$. The value of $x$ is . . . . . . .

$A$ transistor is operated in common emitter configuration at $V_C = 2 \, V$ such that a change in the base current from $100 \, \mu A$ to $300 \, \mu A$ produces a change in the collector current from $10 \, mA$ to $20 \, mA$. The current gain is