In electric circuit, the energy carriers are free electrons.

COULOMB – basic unit of electric charge

***To produce 1 coulomb of electric charge, 6.3 x 10 by 18 electrons are required.

ELECTRIC CURRENT

When charges move in a material, current is

produced. The current tells the rate of flow of

charges in it,

Current (I) = amount of charge (Q)

Time (t)

Ampere (A) – unit of current

1 A = 1 Coulomb per second (C/s)

***If the current in an electric circuit says 5 A,

there are 5 C of charge that flow past a point in one second.

1 ampere = there are 6.3 x

10^18 electrons (1 Coulomb)

passing a cross section in 1 second

If current through a flashlight bulb is 0.3 A, how many

electrons will pass at any point in the flashlight circuit

every second?

1 a = 1C/ sec

= 0.3 A/sec x sec / 6.3 x 10^18 C

= 0.048 A

C= It= (0.048 C/sec) (1 sec) = 0.048 C

AC ( alternating current)

DC (Direct current)

Types of Current

What is Direct Current?A battery

produces direct current

in a circuit because the

terminals have the

same opposite charges.

A kind of current in household

circuits wherein there is a

continuous back and forth

movement of electrons in the

circuit.

What is alternating current?

Direct Current

DC Provided by batteries

Alternating Current

AC Provided by power companies