what is ohms law.?

Answer 1

Ohm's law states that, in an electrical circuit, the current passing through most materials is directly proportional to the potential difference applied across them

In mathematical terms, this is written as:

where I is the current, V is the potential difference, and R is a proportionality 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.

Answer 2

Ohm's law states that, in an electrical circuit, the current passing through most materials is directly proportional to the potential difference applied across them.
A voltage source, V, drives an electric current, I , through resistor, R, the three quantities obeying Ohm's law: V = IR
Enlarge
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 = \frac VR,

where I is the current, V is the potential difference, and R is a proportionality 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 is named after the physicist Georg Ohm, who published it in 1826.

Answer 3

in electricity, experimentally discovered relationship that the amount of steady current through a large number of materials is directly proportional to the potential difference, or voltage, across the materials. Thus, if the voltage V (in units of volts) between two ends of a wire made from one of these materials is tripled, the current I (amperes) also triples; and the quotient V/I remains constant. The quotient V/I for a given piece of material is called its resistance, R, measured in units named ohms. The resistance of materials for which Ohm's law is valid does not change over enormous ranges of voltage and current. Ohm's law may be expressed mathematically as V/I = R. That the resistance, or the ratio of voltage to current, for all or part of an electric circuit at a fixed temperature is generally constant had been established by 1827 as a result of the investigations of the German physicist Georg Simon Ohm.

Alternate statements of Ohm's law are that the current I in a conductor equals the potential difference V across the conductor divided by the resistance of the conductor, or simply I = V/R, and that the potential difference across a conductor equals the product of the current in the conductor and its resistance, V = IR. In a circuit in which the potential difference, or voltage, is constant, the current may be decreased by adding more resistance or increased byremoving some resistance. Ohm's law may also be expressed in terms of the electromotive force, or voltage, E, of the source of electric energy, such as a battery. For example, I = E/R.

With modifications, Ohm's law also applies to alternating-current circuits, in which the relation between the voltage and the current is more complicated than for direct currents. Precisely because the current is varying, besides resistance, other forms of opposition to the current arise, called reactance. The combination of resistance and reactance is called impedance, Z. When the impedance, equivalent to the ratio of voltage to current, in an alternating current circuit is constant, a common occurrence, Ohm's law is applicable. For example, V/I = Z.

Answer 4

Consider an electrical circuit with current I (unit amperes) and potential difference V (unit Volts) applied between the two terminals. Acording to Ohm's law the potential difference applied between the two terminals is directly proportional to the current passing through the two terminals. This means as the applied potential diff. btwn the two terminals increases the current flowing too increases. This brings the concept of resistance into play which is the amount of resistance the medium can offer to flow of current (unit Ohms). The current is obviously inversely proportional to the resistance value. Hence Ohm's law can be stated as I is directly prop. to V or I is inversely prop. to R. Or I=V/R.

Answer 5

Ohm's law states that, in an electrical circuit, the current passing through most materials is directly proportional to the potential difference applied across them.
A voltage source, V, drives an electric current, I , through resistor, R, the three quantities obeying Ohm's law: V = IR
Enlarge
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 = \frac VR,

where I is the current, V is the potential difference, and R is a proportionality 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 is named after the physicist Georg Ohm, who published it in 1826.

Overview

The law as published by Ohm applied specifically to his experiments with conduction in metallic wires. Later, when electronic circuits were created that required a wider range of resistances in a compact form, resistors were manufactured from nonmetals that obeyed Ohm's Law. Metallic and nonmetallic resistors are called ohmic devices, because they obey Ohm's Law, at least within certain limits of voltage and current.

Outside these limits, the resistance of an ohmic device varies with the voltage and current. Finally, at extremely high voltages, the device may suffer from electric breakdown or arcing, causing a short circuit; or, at high currents, the device may overheat and melt, causing an open circuit. The resistance of most devices also varies with their temperature, and more specialised devices have resistances that vary with magnetic field intensity, light intensity or many other stimuli.

The relation V = IR can also be applied to non-ohmic devices, but it then ceases to represent Ohm's Law. In non-ohmic cases, R depends on V and is no longer a constant of proportionality but a variable called differential resistance. To check whether a given device is ohmic or not, one plots V versus I and checks that the curve is a straight line.

Answer 6

Ohms law relates the current and voltage. It states that the steady current flowing through a conductor s directly proportional to the potential difference in between the two ends of the conductor.
I directly proportinal to V
ie., I=kV
where k is constant of proprtionality
.....I= V/R ......k=1/R

Answer 7

Ohm's Law states that "When the physical conditions are kept constant(ie, temp,..) Then for a given current carrying conductor the current flowing through it is proportional to the voltage applied across it's ends."

ie, V is Proportional to I (V=voltage applied across it's end and I=current flowing through it.)


So V=R*I where R is the constant of proportionality. It is also called the resistance of the conductor.

Answer 8

V=I R

Voltage=Current times Resistance

Answer 9

ohms law gives the relation between the current flowing through a conductor & the potential difference across its ends.
according to it I is directly propotional to V

Answer 10

Ohm's law states that, in an electrical circuit, the current passing through most materials is directly proportional to the potential difference applied across them.

A voltage source, V, drives an electric current, I , through resistor, R, the three quantities obeying Ohm's law: V = IR
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 is named after the physicist Georg Ohm, who published it in 1826.

(Hydraulic analogy:
While the terms voltage, current and resistance are fairly intuitive terms, beginning students of electrical engineering might find the analog terms for water flow helpful. Water pressure, typically measured in pounds per square inch, is the analog of voltage because establishing a water pressure difference between two points along a (horizontal) pipe causes water to flow. Water flow rate, as in gallons of water per minute, is the analog of current, as in coulombs per second. Finally, flow restrictors such as apertures placed in pipes between points where the water pressure is measured are the analog of resistors. We say that the rate of water flow through an aperture restrictor is proportional to the difference in water pressure across the restrictor. Similarly, the rate of flow of electrical charge, i.e. the electrical current, passing through an electrical resistor is proportional to the difference in voltage measured across the resistor.)