Q. If $R_{P} = 7k\Omega,\ g_{m} = 2.5\ millimho$, then on increasing plate voltage by $50V,$ how much the grid voltage is changed so that plate current remains the same
A) $- 2.86\ V$
B) $- 4\ V$
C) $+ 4\ V$
D) $+ 2\ V$
Explanation
(a) By using $\mu = - \frac{\mathrm{\Delta}V_{p}}{\mathrm{\Delta}V_{g}} = r_{p} \times g_{m}$
$\Rightarrow 7 \times 10^{3} \times 2.5 \times 10^{- 3} = - \frac{50}{\mathrm{\Delta}V_{g}} \Rightarrow \mathrm{\Delta}V_{g} = - 2.86$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.