Figures $${\rm I}$$ and $${\rm I}{\rm I}$$ show two MOS capacitor of unit area. The capacitor in Figure I has insulator materials X (of thickness t₁ = 1 nm and dielectric constant $${\varepsilon _1}$$ = 4) and Y (of thickness t₂ =3 nm and dielectric constant $${\varepsilon _2}$$ = 200). The capacitor in Figure $${\rm I}{\rm I}$$ has only insulator material X of thickness t_eq. If the capacitors are of equal capacitance, then the value of t_eq (in nm) is ______

In the circuit shown in the figure, the channel length modulation of all transistors is non-zero $$\left( {\lambda \ne 0} \right)$$. Also all transistors operate in saturation and have negligible body effect. The ac small signal voltage gain $$\left( {{V_0}/{V_{in}}} \right)$$ of the circuit is

In the circuit shown in the figure, transistor M1 is in saturation and has transconductance g_m = 0.01 siemens. Ignoring internal parasitic capacitances and assuming the channel length modulation $$\lambda $$ to be zero, the small signal input pole frequency (in kHz) is _____

Consider a long-channel NMOS transistor with source and body connected together. Assume that the electron mobility is independent of V_GS and V_DS. Given,
g_m = 0.5$$\mu {\rm A}/V$$ for V_DS = 50 m V and V_GS = 2V,
g_d = $$8\mu {\rm A}/V$$ for V_GS = 2 V and V_DS = 0 V,
Where g_m =$${{\partial {{\rm I}_D}} \over {\partial {V_{GS}}}}\,\,and\,\,{g_d}\,\, = \,{{\partial {{\rm I}_D}} \over {\partial {V_{DS}}}}$$

The threshold voltage (in volts) of the transistor is