2. Electric Current
Electric current is a measure of the amount of
electrical charge transferred per unit time. It represents
the flow of electron through a conductive material
Electric current is similar to a
current of water, but electric
current flows in solid metal wires
so it is not visible.
Electric current can carry a lot of
power.
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3. ELECTRIC CURRENT
An ELECTRIC CURRENT exists whenever electric charge flows
through a region, e.g., a simple light bulb circuit.
The magnitude of the current is measured in AMPERES (Amps/A)
1 ampere = 1 coulomb/second
4. Electric Circuits
An electric circuit is something that provides a
complete path through which electricity travels.
Wires in electric circuits are similar in some
ways to pipes and hoses that carry water.
6. Voltage
Voltage is the electrical force, or
"pressure", that causes current to flow in a
circuit. Voltage is measured in volts (V).
A voltage difference of 1 volt means 1 amp of
current does 1 joule of work in 1 second.
7. Electrical Resistance
Resistance measures how difficult it is for current
to flow.
The total amount of electrical resistance in a circuit
determines the amount of current that in the circuit for a
given voltage.
The more resistance the circuit has, the less current that
flows.
The SI unit of resistance is the ohm (Ω).
One ohm is the resistance when a
voltage of 1 volt is applied with a current
of 1 amp.
8. Ohm’s Law
Georg Simon Ohm (1787-1854), A German
physicist, discovered Ohm’s law in 1826.
Statement of Ohm's Law
The current through a conductor is proportional to the
potential difference between its ends, provided the
temperature of the conductor remains constant.
9. Ohm’s Law
Georg Ohm showed that the flow of an electric current
through a wire depended on its 'resistance' and the
potential difference between its ends
A graph drawn between the voltmeter readings and ammeter
readings, shows a straight line pattern. The straight line
indicates a relationship and is named as ohm's law.
Expressed mathematically,
10. Ohm’s Law: Resistance And
Resistors
The ratio of voltage to current is called the
resistance
In many conductors, the resistance is independent
of the voltage; this relationship is called Ohm’s
law.
11. Electrical Resistor
Resistor is used to control the amount of current flowing in a
circuit
The two main types of resistors :
Wire-wound (coil of fine wire) resistors
Composition (carbon) resistors
Electric resistance is the ratio of one volt and one ampere.
Or We can say that Ohm is the unit of Electric resistance.
Electrical components called resistors can be used to control
current.
12. Ohm’s Law
Ohm’s law gives a relationship between the voltage (V), current
(I), and resistance (R) as follows:
V = I R
13. The End
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