GATE EC 2024 Question Paper (11-Feb-2024) (Shift 1)

Consider a MOS capacitor made with p-type silicon. It has an oxide thickness of 100 nm, a fixed positive oxide charge of $10^{-8}$ C/cm${}^2$ at the oxide-silicon interface, and a metal work function of 4.6 eV. Assume that the relative permittivity of the oxide is 4 and the absolute permittivity of free space is $8.85\times 10^{-14}$ F/cm. If the flatband voltage is 0 V, the work function of the p-type silicon (in eV, rounded off to two decimal places) is ________.

In the network shown below, maximum power is to be transferred to the load $R_L$.

The value of $R_L$ (in $\Omega$) is ________.

A non-degenerate n-type semiconductor has 5% neutral dopant atoms. Its Fermi level is located at 0.25 eV below the conduction band ($E_c$) and the donor energy level ($E_D$) has a degeneracy of 2. Assuming the thermal voltage to be 20 mV, the difference between $E_c$ and $E_D$ (in eV, rounded off to two decimal places) is ________.

An NMOS transistor operating in the linear region has $I_{DS}$ of 5 $\mu$ A at $V_{DS}$ of 0.1 V. Keeping $V_{GS}$ constant, the $V_{DS}$ is increased to 1.5 V.
Given that ${\mu }_n{C}_{ox}\frac{W}{L}=50\mu$ A/V${}^2$, the transconductance at the new operating point (in $\mu$ A/V, rounded off to two decimal places) is ________.

The photocurrent of a PN junction diode solar cell is 1 mA. The voltage corresponding to its maximum power point is 0.3 V. If the thermal voltage is 30 mV, the reverse saturation current of the diode (in nA, rounded off to two decimal places) is ________.