2. What is electricity???
Electricity is the set of physical phenomena
associated with the presence and flow of
electric charges.
Electricity -by Molly Rathore
12/25/2013
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3. ELECTRIC CHARGES
Types of charges :
1. Positive Charges
2. Negative Charges
Properties of charges :
1. Unlike charges attract each other.
2. Like charges repel each other.
3. Electric charges are additive in
nature.
4. Electric charges are quantized.
Q = ne , Q=charge transferred
Electricity -by Molly Rathore
n=No. of electrons
12/25/2013
e=charge on electron
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4. ELECTRIC CURRENT
If the electric charge flows through a
conductor, we say that there is an electric
current in the conductor.
Electric current is expressed as the
amount of charge flowing through a
particular area in unit time. In other
words, it is the rate of flow of charges.
Electricity -by Molly Rathore
12/25/2013
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5. If a net charge Q, flows across any cross
section of a conductor in time t, then the
current I, through the cross section is
I = Q/t
The S.I. unit of electric charge is coulomb ,
which is equivalent to the charge contained
in 6.25 X 1018 electrons.
An electron possesses a negative charge of
1.6 X 10-19 C.
Electricity -by Molly Rathore
12/25/2013
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6. Conventionally, in an electric circuit the
direction of electric current Is take as
opposite to the direction of the flow of
electrons, which are negative charges.
Electricity -by Molly Rathore
12/25/2013
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7. ELECTRIC CIRCUIT
O A continuous and closed path of an
electric current is called electric circuit.
O If the circuit is broken anywhere, the
current stops flowing.
CLOSED CIRCUIT DIAGRAM
Electricity -by Molly Rathore
OPEN CIRCUIT DIAGRAM
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