Question

Let i_E, i_C and i_B represent the emitter current, the collector current and the base current respectively in a transistor. Then
(a) i_C is slightly smaller than i_E
(b) i_C is slightly greater than i_E
(c) i_B is much smaller than i_E
(d) i_B is much greater than i_E.

Answer 1

(a) i_C is slightly smaller than i_E
(c) i_B is much smaller than i_E
The highlighted parts could not be edited, as the meaning could not be understood. Also, please check the last line for logical accuracy. Only one option is given as correct, while the solution gives two correct options.
We know that in the transistor base is slightly doped, therefore when the majority carriers due to forward biasing of emitter base junction, feel the repulsive force from the battery and pass over to the base region. This gives the emitter current i_E.
As the base is thin and lightly doped, only few majority carriers of the emitter are neutralised at the base. This gives the base current. Hence, base current $\left(i_B\right)$ is low.
The remaining majority carriers of the emitter pass to the collector and give collector current i_C.
Thus, we get the relation given below:
i_E = i_B + i_C

Thus, because of the base, current i_C is slightly smaller than i_E .
Hence, option (a) and (c) are correct.