GATE EC 2014 Question Paper (15-Feb-2014) (Shift 1)

A depletion type N-channel MOSFET is biased in its linear region for use as a voltage controlled resistor. Assume threshold voltage V${}_{TH}$ = - 0.5 V, V${}_{GS}$ = 2.0 V, V${}_{DS}$ = 5 V, W/L = 100, C${}_{OX}$ = 10⁻⁸ F/cm² and μₙ = 800 cm²/V-s. The value of the resistance of the voltage controlled resistor (in Ω) is _________.

In the voltage regulator circuit shown in the figure, the op-amp is ideal. The BJT has V${}_{BE}$ = 0.7 V and β = 100, and the Zener voltage is 4.7 V. For a regulated output of 9 V, the value of R (in Ω) is _____.

In the circuit shown, the op-amp has finite input impedance, infinite voltage gain, and zero input offset voltage. The output voltage Vₒᵤₜ is

For the amplifier shown in the figure, the BJT parameters are V${}_{BE}$ = 0.7 V, β = 200, and thermal voltage V${}_T$ = 25 mV. The voltage gain (vₒ/vᵢ) of the amplifier is _______ .

The output 𝐹 in the digital logic circuit shown in the figure is