The grid voltage of any triode valve is changed from –1 volt to –3 volt and the mutual conductance is $3 × 10^{–4}$ mho. The change in plate circuit current will be
Answer & explanation
Correct answer: option 2
$g_m=\frac{ΔI_p}{ΔV_g}$
or $ΔI_p= g_m× ΔV_g=3 × 10^{–4}× [- 3 -(- 1)] =0.6 ×10^{-3} A$ shortage of $0.6 ×10^{-3} A$