Basics of Electric
Current
Electric Current is the
flow of charge. Charge here refers to ions or electrons.
Hence we can define Electric Current as flow of electrons
through electronic components. We
can say in more simpler terms current is flow of electrons.
We know that like charges
repel and unlike charges attract each other. In Other Words
Negative-Negative repels each other and
Positive-Negative attracts each other.
For example we have to glow an electric
bulb then a negative end of a 9volt battery will
drive negative electrons along an electric wire. The
positive end of a 9volt battery will attract negative
electrons along an electric wire. Electric current will
therefore flow from the negative terminal of a battery
through the electric bulb to the positive terminal and will
glow the electric bulb.
The SI unit of electric current intensity is the ampere.
Electric current is measured using an
ammeter. The current
I in amperes can be computed with the following Formula:
I=Q/T
Q-Electric Charge in
Columbs
T-Time in Seconds
Electric current can also
be called as the time rate of change of charge
I=DQ/DT
Density of Electric Current
Current density is a
measure of the density of an electric current. The current
density is measured in amperes per square meter.
Drift Speed Computation of electric charges
I=NaVQ
-
I is the electric current
-
N is number of charged
particles per unit volume
-
a is the cross-sectional
area
-
V is the drift velocity
-
Q is the charge on each
particle.
Ohms Laws -Electric
Current
-
V=IR where
V=Potential Difference, I=Current, R=Resistance
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