Chapter 4, Problem 3P

The Weibull distribution is widely used in statistical problems relating to aging of solid insulating materials subjected to aging and stress. Use this distribution as a model for time (in hours) to failure of solid insulating specimens subjected to AC voltage. The values of the parameters depend on the voltage and temperature; suppose ? = 2.2 and ? = 220. (a) What is the probability that a specimen's lifetime is at most 250? Less than 250? More than 300? (Round your answers to five decimal places.) at most 250 less than 250more than 300 (b) What is the probability that a specimen's lifetime is between 100 and 250? (Round your answer to four decimal places.)   (c) What value (in hr) is such that exactly 50% of all specimens have lifetimes exceeding that value? (Round your answer to three decimal places.)  hr

If you wish to decrease the amount of current in a resistor from 240mA to 180mA by changing the 24V source, what should be the new voltage setting be?

Calculate the effect that increasing the overpotential from 0.50 V to 0.60 V has on the current density in the electrolysis of 1.0 m NaOH(aq), which is 1.22 mA cm−2 at 0.50 V and 25 °C. Take α = 0.50.