In the circuit shown, both the enhancement mode NMOS transistors have the following characteristics: k_n = $${\mu _n}{C_{ox}}(W/L) = 1m{\rm A}/{V^2}$$ ; V_TN = 1V. Asuume that the channel length modulation parameter $$\lambda $$ is zero and body is shorted to source. The minimum supply voltage V_DD (in volts) needed to ensure that transistor M₁ operates in saturation mode of operation is _____

The current in an enhancement mode NMOS transistor biased in saturation mode was measured to be 1 mA at a drain-source voltage of 5 V. When the drain-source voltage was increased to 6 V while keeping gate-source voltage same, the drain current increased to 1.02 mA. Assume that drain to source saturation voltage is much smaller than the applied drain-source voltage. The channel length modulation p[arameter $$\lambda $$ (in V^-1) is _______

For $$A = \left[ {\matrix{ 1 & {\tan x} \cr { - \tan x} & 1 \cr } } \right],$$ the determinant of $${A^T}\,{A^{ - 1}}$$ is

The value of $$\sum\limits_{n = 0}^\infty {n{{\left( {{1 \over 2}} \right)}^n}\,\,} $$ is _______.