Chapter 4, Problem 15P

There is a series type ohmmeter, designed to operate on a 6 V battery. The galvanometer has an internal resistance of 2000 ohms and requires a current of 100 μA for full full scale deflection. The value of R1 is 49 k ohms. If the battery voltage has dropped to 5.9 V, determine the necessary value of R2 to zero the meter; b) According to the conditions indicated in the previous paragraph, an unknown resistance is connected to the meter giving a deflection of 60%. Calculate the value of the unknown resistance.

What is the purpose of waiting 1s after a voltage pulse before measuring current in sampled current voltammetry?

You have a 2.50 cm diameter sphere that you would like to have plated with platinum metal.  How long will it take to electroplate a 40.0 micron thick coating onto the sphere using Pt+2 and a current of 0.500 amps?  The density of platinum is 21.45 g/cm3.  1 micron = 1.00×10–4 cm.[hint:  Calculate the difference in volume of the coated and uncoated spheres and then use the density information to determine your answer.]Time Required = Answer minutes