(a) random movement of electrons
in a conductor
(b) movement of free electrons predominately in one direction
(c) pressure difference between two poles
(d) power that causes drift of electrons
Correct Answer: (b) movement
of free electrons predominately in one direction
Explanation
Random motion of electrons
exists due to thermal energy, but electric current is defined as the directed
drift of electrons due to applied voltage.
Notes for
More Information
• Drift
velocity is very small
• Conventional
current flows from positive to negative terminal
• Directional motion is essential for current
• Electric
current is an electrical phenomenon caused by the movement
of free electrons from one atom to another.
• It means
the continuous movement of free electrons mainly in one
direction.
• When
electrons move through a conductor, electric current flows.
• Electric
current is defined as the amount of electric charge flowing through a
given area per unit time.
• In simple
words, electric current is the rate of flow of electric charges.
• In electric
circuits made of metallic wires, electrons are the
actual charge carriers.
• In earlier
times, electrons were not known, so scientists assumed current to
be the flow of positive charges.
• Because of
this assumption, the direction of current was taken as the
direction in which positive charges would flow.
• Therefore, by
convention, the direction of electric current is opposite to the
actual direction of electron flow.
