It’s possible to save a great deal of electrical energy (and money and natural resources) with some simple changes in household electrical use. The trouble is that most of these changes mean either changing behavior or spending money. Do an Internet search and review a few ways to save electrical energy. Discuss at least one change that you think would be reasonable and worthwhile to do in your own home in the next year. Provide your rationale.

What is the conversion factor between kg/m^3 and g/m^3. express your experimental values for the densities in kg/m^3.

Search coils and credit cards. one practical way to measure magnetic field strength uses a small, closely wound coil called a search coil. the coil is initially held with its plane perpendicular to a magnetic field. the coil is then either quickly rotated a quarter-turn about a diameter or quickly pulled out of the field. (a) derive the equation relating the total charge q that flows through a search coil to the magnetic-field magnitude b. the search coil has n turns, each with area a, and the flux through the coil is decreased from its initial maximum value to zero in a time ∆t. the resistance of the coil is r, and the total charge is q = i∆t, where i is the average current induced by the change in flux. (b) in a credit card reader, the magnetic strip on the back of a credit card is rapidly “swiped” past a coil within the reader. explain, using the same ideas that underlie the operation of a search coil, how the reader can decode the information stored in the pattern of magnetization on the strip. (c) is it necessary that the credit card be “swiped” through the reader at exactly the right speed? why or why not?

Which lists the pairs of plates in order from least to greatest in terms of the work done to move the electron?