9781422275993

SCIENCE FACTS

● ● Alternating current was used for the first time by a French neurologist, Guillaume Duchenne in 1855. ● ● Electricity travels at the speed of about 186 miles (300 km) per second, similar to light.

Types of Electric Current Depending on the flow of charges, electric current is further divided into two types. These are alternating current and direct current. Alternating current, or AC, is the current which changes its flow direction after every fixed time span. On the other hand, direct cur- rent, or DC, is the type of current which does not change its flow direction.

High voltage transmission lines deliver power from electric generation plants over long distances using alternating current.

13

ELECTRICITY