MOSFET has the gate length L = 0.6 um, the width W = 10 um, the oxide thickness 4.5 nm and the relative dielectric permittivity 3.9. The electron mobility is 365 cm^2/Vs, the gate-threshold voltage offset V_GT = 3.3 V and the characteristic velocity saturation field Fs = 1.4 e4 V/cm.

a. For the drain voltage corresponding to the onset of saturation, find the channel sheet carrier density ns_dr at the drain end of the channel.
b. Find the saturation current, Isat

Determine the time of the day and month of the year at which the peak sensible cooling load occurs for a top floor, north-eastern corner room of an office building in durban for the following conditions: floor area: 8 x 8 x 3 m east and north walls: 115 mm face brick (outside), 20 mm air space, 115 mm ordinary brick (inside) with 15 mm plaster roof construction: suspended plasterboard ceiling, 450 mm air space, 150 mm concrete, 75mm screed, waterproofing no heat transfer across other surfaces window area 3x 1,5 m high in north wall only. ordinary glass with venetian blinds. lights and occupants : from 07: 00 to 18: 00 average light density: 25 w/m2 number of occupants : 5 seated, light office work room temperature 24°c