Back, Sir George, 1796-1878, British explorer in N Canada. He accompanied Sir John Franklin on arctic expeditions in 1818, 1819-22, and 1824-27. On an expedition (1833-35) to search for the missing John Ross, Back explored the Great Fish River (now Back River) and Montreal Island in the present Nunavut Territory. His Narrative of the Arctic Land Expedition appeared in 1836. On a later journey (1836-37) he explored the arctic coast of Canada.

Back, river, c.600 mi (970 km) long, rising in lakes, Northwest Territories, Canada, and flowing northeast through Nunavut across the tundra to Chantry Inlet. Numerous lakes lie along its course. It is named for Sir George Back, the first European to descend the river (1834).

Telecommunications

In telecommunications, a back-to-back connection is a direct connection between either:

1. the output of a transmitting device and the input of an associated receiving device. When used for equipment measurements or testing purposes, such a back-to-back connection eliminates the effects of the transmission channel or medium.
2. the output of a receiving device and the input to a transmitting device.

The term direct may be construed as permitting a passive device such as a pad to accommodate power level constraints.

Source: from Federal Standard 1037C and from MIL-STD-188

Electronics

A back to back connection is 2 idenitcal or similar components connected in series with the opposite polarity. This is used to convert polarised components to non-polar use. Common examples include:

• electrolytic capacitors
• zener diodes