A Silicon PN junction at a temperature of 20°C has a reverse saturation current of 10 pico-Amperes (pA). The reverse saturation current at 40°C for the same bias is approximately

The impurity commonly used for realizing the base region of a silicon n-p-n transistor is

n-type silicon is obtained by doping silicon with

The intrinsic carrier concentration of silicon sample at 300^oK is $$1.5\times10^{16}/m^3$$. If after doping, the number of majority carriers is $$5\times10^{20}/m^3$$ , minority carrier density is