$A$ transistor has a voltage gain '$A$'. If a fraction '$\beta$' of its output is fed back to the input of the transistor,then the transistor becomes an oscillator when:

If the value of $R_e$ is zero then voltage gain is $200$. Find the voltage gain when $R_e$ is $2 \, k\Omega$.

In a $CE$ circuit,the collector of a transistor is kept at a constant voltage $V_C = 1.5 \ V$. When the base current changes from $100 \ \mu A$ to $150 \ \mu A$,the collector current changes from $5 \ mA$ to $10 \ mA$. The current gain $\beta$ for this transistor is:

In a common emitter transistor,the current gain is $80$. What is the change in collector current,when the change in base current is $250 \ \mu A$?

In a study of a transistor as an amplifier,the ratio of collector current to emitter current is $0.98$. If the collector current is $3 \text{ mA}$,then the base current will be approximately:

$A$ transistor having a $\beta$ equal to $80$ has a change in base current of $250 \mu A$. What is the change in collector current?