what is Ohm's law?

Answer 1

Voltage = Current x Resistance.

The current flowing in a wire (amperes) is directly proportional to
the voltage across that wire (volts).

Also Current = Voltage/resistance and
Resistance = voltage/current.

Answer 2

This is the best web-page I found which is the simplest and the most comprehensive.


Ohm's law states that, in an electrical circuit, the current passing through a conductor, from one terminal point on the conductor to another terminal point on the conductor, is directly proportional to the potential difference (i.e. voltage drop or voltage) across the two terminal points and inversely proportional to the resistance of the conductor between the two terminal points.

For real devices (resistors, in particular), this law is usually valid over a large range of values of current and voltage, but exceeding certain limitations may result in losing simple direct proportionality (e.g. temperature effects, see below).


A voltage source, V, drives an electric current, I , through resistor, R, the three quantities obeying Ohm's law: V = IR.In mathematical terms, this is written as:

I=V/R

,
where I is the current, V is the potential difference, and R is a constant called the resistance. The potential difference is also known as the voltage drop, and is sometimes denoted by E or U instead of V.

The SI unit of current is the ampere; that of potential difference is the volt; and that of resistance is the ohm, equal to one volt per ampere.

The law was named after the physicist Georg Ohm, who, in a treatise published in 1827, described measurements of applied voltage, and current passing through, simple electrical circuits containing various lengths of wire, and presented a slightly more complex equation than the above equation to explain his experimental results. The equation above could not exist until the ohm, a unit of resistance, was defined (1861, 1864).

Answer 3

Ohm's law states that electrical current and voltage are directly proportionate, therefore
U=R x I
Where U is the voltage, I is the current
And the constant R is called electrical resistance.
So, Ohm's law not only gives the above formula, but also states that R is constant. And this is not necessarily true (for diodes for instance)

There is a second version of the law, on a microscopic level. It states that current density (j) is in direct proportion to the electric field E.
j=s x E
where the constant s (sigma actually) is called conductivity.

Answer 4

Ohms law is a relationship between current, voltage and resistance. Ohms law says
V=IR
V=potential difference in Volts
I= Current in Amps
R=resistance in ohms

Answer 5

It is a theory concerning the flow of electricity through a substance such as a wire. It says that the rate of flow of the current is proportional to the voltage, or potential difference, across the wire while that current is flowing.
The ratio of the voltage (measured in volts) to the current (measured in Amps) is called the resistance, measured in Ohms.

Of course in real life it gets more complicated than that, as temperature affects the resistance.
Do a search for Ohms in Wikipedia.

Answer 6

OHM"S LAW states that "the current(I) flowing through two points of a conductor is directly proportional to the potential difference(V) across them provided that some physical conditions such as temperature are kept constant"

Answer 7

The voltage across a resistance is equal to the product of the current through the resistance and the value of the resistance. Or, as everybody else says, E=IR. That is the physics. In practical every-day things, one of the implications is that electrical currents will divide and return to their source (completing the circuit) by absolutely every path available and divide themselves according the the amount of resistance in each path. So, the signal in the right channel of your stereo doesn't all come back on the shield of the right channel cable. Some if it will come back on the shield of the left channel. Or the ground lead in the power cord. Absolutely every path. Makes yous stereo hum and electronics engineers crazy.

Answer 8

Ohm's law describes the relationship between current, voltage and resistance in a conductor. In its simplest form it is:

V=IR

Where V=voltage (in volts), I=current (in amps) and R=resistance (in Ohms).

Answer 9

V=I*R

Potential difference (volts) = Current (amperes) * Resistance (ohms)

Answer 10

I = V/R I is current in amps, v is voltage and R is resistance,.