Problem 1:
a. Using the characteristics of given Figure, determine the resistance of the photoconductive cell at 10 and 100 foot-candles of illuminaton. As in Problem 2, note that it is a log scale.
b. Does the cell have a positive or a negative illumination coefficient?
c. Is the coefficient a fixed value for the range 0.1 to 1000 foot-candles? Why?
d. What is the approximate rate of change of R with illumination at 10 foot-candles?
Problem 2
a. Find the resistance of the thermistor having the characteristics of given Figure at -50°C, 50°C, and 200°C. Note that it is a log scale. If necessary, consult a reference with an expanded log scale.
b. Does the thermistor have a positive or a negative temperature coefficient?
c. Is the coefficient a fixed value for the range -100°C to 400°C? Why?
d. What is the approximate rate of change of with temperature at 100°C?
