description of ohms law in a simple way...

1. OHM’S LAW
PHYSICS PROJECT
ON

2. GEORGE SIMON OHM
{1787-1854}
Georg Simon Ohm was a German physicist
born in Erlangen, Bavaria, on March 16, 1789.
Ohm’s main interest was current electricity,
which had recently been advanced by
Alessandro Volta’s invention of the battery.
Ohm made only a modest living and as a result
his experimental equipment was primitive.
Despite this, he made his own metal wire,
producing a range of thickness and lengths of
remarkable consistent quality. The nine years
he spent at the Jesuit’s college, he did
considerable experimental research on the
nature of electric circuits. He took considerable
pains to be brutally accurate with every detail of
his work. In 1827, he was able to show from his
experiments that there was a simple
relationship between resistance, current and
voltage.
.

3. OHM’S LAW
Acc. To Ohm’s Law, if the conditions are unchanged (like – temp.), the
potential difference flowing through the two ends of the conductor is
directly proportional to electric current flowing through it & the electric
current is inversely proportional to the resistance.
V is the voltage of the resistor, measured in Volts (V). In some cases
Ohm's law uses the letter E to represent voltage. E denotes electromotive
force(emf). I is the electrical current flowing through the resistor,
measured in Amperes (A) & R is the resistance of the resistor, measured
in Ohms (Ω).

4. When we know the voltage & current , we can easily find the resistance
of that particular circuit by ohm’s law i.e
V=IR so, R= V
R
The resistance R in ohms (Ω) is equal to the voltage V in
volts (V) divided by the current I in amps (A)
When we know the resistance & current, we can easily find the voltage
of that particular circuit by ohm’s law :
V=IR
The voltage V in volts (V) is equal to the to the current I in
amps (A) times the resistance R in ohms (Ω):

5. FACTORS ON WHICH
STRENGTH OF ELECTRIC
CURRENT DEPEND
As earlier stated, since the current is directly
proportional to the potential difference applied across
the ends of a conductor, it means that if the potential
difference across the ends of a conductor is doubled,
current flowing through it also gets doubled, and if the
potential difference is halved, the current also gets
. On the other hand, the current is inversely proportional
to resistance. So, if the current is doubled the current
gets halved, and if the resistance is halved, the current
gets doubled. Thus, the strength of an electric current
given conductor depends on two factors :
I. potential difference across the ends of the
conductor, and
II. resistance of the conductor.

6. RESISTANCE OF A CONDUCTOR
The electric current is a flow of electrons through a conductor. When the
electrons move from one of the conductor to the other part, they collide with
other electrons and with the atoms and ions present in the body of the
conductor. Due to these collisions, there is some obstructions or oppositions
to the flow of electronic current through the conductor. The property of a
conductor due to which it opposes the flow of current through it is
resistance of a conductor is numerically equal to the ratio of potential
difference across its ends to the current flowing through it.
The resistance of a conductor depends on length, thickness, nature of the
material and temperature, of the conductor. A long wire (or a conductor) has
more resistance and a short wire has less resistance. Again, a thick wire has
less resistance whereas a thin wire has more resistance. Rise in temperature
of a wire (or a conductor) increases its temperature.
The SI unit of resistance is Ohm which is denoted by a Greek letter

7. ONE OHM {Ω}
The unit of resistance is ohm, can be defined by using Ohm's Law:
Acc. To Ohm’s Law,
Potential diff./Current = Resistance (at constant)
So Resistance {R},
R= V/I
SO, if the potential difference V is 1 volt and the current I is 1 ampere, then resistance R in the above equation becomes 1 ohm.
Mathematically,
1 OHM = 1 VOLT / 1 AMPERE
This gives us the following definition for ohm : 1 ohmis theresistanceof a conductorsuchthatwhena potentialdifferenceof 1
voltis appliedto itsends,a currentof 1 ampereflowsthroughit.

8. THANK YOU FOR WATCHING
PRESENTED BY
VIJAY PRATAP
CLASS-X
ROLL.NO-36
K.V.NO.2 KRIBHCO,SURAT