complete slides about

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TOPIC: RESISTORS

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GROUP::B
1MOHAMMAD YOUSIF
2 KASHIF HASHMI
3 MUHAMMAD FUZAIL

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what is resisitor?
A resistor is a passive two-terminal
electrical component that implements
electrical resistance as a circuit element.

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 Resistors act to reduce current flow.
 Resistors absorb power from a circuit and
convert it into heat
 In electronic circuits resistors are used to limit
current flow, to adjust signal levels.

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History of resisitor
The Resistance was
discovered by the
year 1827 from Georg
Simon Ohm, a
German electrician.
Ohm was born in
Germany, in the city of
Erlangen at 1787 and
died at 1854.

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formula for resisitor and unit
 G.S.Ohm described this behavior and gave the name
"Resistance". He then announced the Ohm's law that
connects the resistance with the voltage and the current
 R=V/I mathemathical formula
 Here R is resisitancs V is volt and I is current.
 The unit of resisitance is ohm (Ω) as memorial to its
inventor

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Working of resisitor
• A resistor is a little
package of resistance:
wire it into a circuit and
you reduce the current by
a precise amount. From
the outside, all resistors
look more or less the
same. As you can can
see in photo, a resistor is
a short, worm-like
component with colored
stripes on the side. It has
two connections, one on
either side, so you can
hook it into a circuit.

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what is resisitance???
• the voltage in volts required to make a
current of 1 amp flow through a circuit. If it
takes 500 volts to make 1 amp flow, the
resistance is 500 ohms (written 500 Ω).
• V = I × R
• This is known as Ohm's Law for German
physicist Georg Simon Ohm (1789–1854).

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how resisitance works??
a ceramic rod running through the
middle with copper wire
wrapped around the outside. A
resistor like this is described
as wire-wound. The number of
copper turns controls the
resistance very precisely: the
more copper turns, and the
thinner the copper, the higher
the resistance. It works by
converting electrical energy
into heat, which is dissipated
into the air.

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How to know the value of a resistor??

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Resisitor colour chart
BLACK: 0
BROWN: 1
RED: 2
ORANGE: 3
YELLOW: 4
GREEN: 5
BLUE: 6
VIOLET: 7
GREY: 8
WHITE: 9
BLACK: 1
BROWN: 10
RED: 100
ORANGE: 1000
YELLOW: 10000
GREEN: 100000
BLUE: 1000000
GOLD: 0.1
SILVER: 0.01
BROWN: 1%
RED: 2%
GOLD: 5%
SILVER: 10%
NOTHING: 20%

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resistors in parallel and in series in circuit

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