Calculate the built-in potential barrier, Vbi, for Si, Ge, and GaAs pn junctions if they each have the following dopantconcentrations at T = 300 It(a) Nd = 1014 cm—3 Na = 1017 cm-3(b) Nd =5 x 1016 Na = 5 x 1016(c) Nd = 1017 Na = 1017

Heat is added to a piston-cylinder device filled with 2 kg of air to raise its temperature 400 c from an initial temperature of t1 27 cand pressure of pi 1 mpa. the process is isobaric process. find a)-the final pressure p2 b)-the heat transfer to the air.

The mass flow rate of the fluid remains constant in all steady flow process. a)- true b)- false

The thermal expansion or contraction of a given metal is a function of the f a)-density b)-initial temperature c)- temperature difference d)- linear coefficient of thermal expansion e)- final temperature f)- original length