Aforward-biased silicon diode is to be used as a temperature sensor. the diode is forward biased with a constant current source and va is measured as a function of temperature. (a) derive an expression for va (t) assuming that d /l for electrons and holes, and eg are independent of temperature. (b) if the diode is biased at id 0.1 ma and if is 1015 a at t 300 k, plot va versus t for 20°c t 200°c. (c) repeat part (b) if id 1 ma. (d) determine any changes in the results of parts (a) through (c) if the change in bandgap energy with temperature is taken into account.