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.
Management is studied at colleges and universities; some important degrees in management are the Bachelor of Commerce (B.Com.) and Master of Business Administration (M.B.A.) and, for the public sector, the Master of Public Administration (MPA) degree.
A standard bachelor's degree in management takes three to four years and will give you a broad management education, with the option to tailor your curriculum to your area of interest. Browse bachelor's degree programs in management.