(b) $V = V_{CE} + I_{C}R_{L}$ $\Rightarrow 15 = 7 + I_{C} \times 2 \times 10^{3} \Rightarrow i_{C} = 4\ mA$ $\because\ \beta = \frac{i_{C}}{i_{B}} \Rightarrow i_{B} = \frac{4}{100} = 0.04\ mA$
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.