Doorbells operate on very low voltage. Older models typically require just 8 to 20 volts of electricity -- most often 16 volts -- while newer models take 24 volts of electricity. Newer models have higher voltage output to accommodate longer runs of wire in larger homes.
Individuals who aim at becoming management researchers or professors may complete the Doctor of Business Administration (DBA) or the PhD in business administration or management. There are three levels of managers, which are typically organized in a hierarchical, pyramid structure.
Doctoral Degree in Business Administration. The doctorate in business administration allows you to concentrate on marketing. The years required to complete the degree vary by school. You typically take classes such as business-to-business marketing, market research and consumer behavior theory. In addition, you must complete a dissertation. While you complete your courses, you may be required to teach undergraduate students.