Silicon is the most widely used semiconductor material for integrated circuits. which of the following are less common semiconductor materials used for ics (two best answers): (a) boron, (b) boron nitride, (c) gallium arsenide, (d) germanium, (e) silicon carbide, (f) silicon dioxide, and (g) zirconium?

Awall of 0.5m thickness is to be constructed from a material which has average thermal conductivity of 1.4 w/mk. the wall is to be insulated with a material having an average thermal conductivity of 0.35 w/mk so that heat loss per square meter shall not exceed 1450 w. assume inner wall surface temperature of 1200°c and outer surface temperature of the insulation to be 15°c. calculate the thickness of insulation required.