Ohms Law


 
 
Concept Explanation
 

Ohms Law

We all have experienced  the situation that when a torch is used for several weeks, its light becomes dim. We say that its cells have become weak.This means that the potential difference has droped to a smaller value because the chemicals have been used up in the chemical reactions. As the potential difference has dropped so less current flows through the bulb, and hence produces less light. So, we can say that the electric current passing through the circuit depends on the potential difference applied across it. The larger is the potential difference, the larger is the current. This relationship between potential difference and current was first discovered by a German physicist Georg Simon Ohm (1787-1854) and is stated by the law named after him

Ohm's Law states that the current passing through a conductor is directly proportional to the potential difference between its ends, provided the physical conditions such as temperature of conductor remain unchanged.

He further observed that as we increase the potential the current increases, so we can state that the

i.e.,         large Vinfty I             or         large V= RI

where R is a constant which is called resistance of the material.

Unit of resistance

large R=frac{V}{I}=frac{volt}{ampere}=ohm(Omega )

The SI unit of resistance is ohm large (Omega ).

If I = 1 Ampere, V = 1 Volt, then R = 1 Omega.

The resistance of a conductor is 1 ohm if a potential difference of 1 volt is produced across its ends when 1 ampere of the current flows through it.

The conductors, which obey the Ohms law are called the ohmic conductors or linear resistances. All metallic conductors (such as silver, aluminium, copper, iron , etc,) are the Ohmic conductors or linear resistances.

The conductors, which do not obey the Ohms law are called the non-Ohmic conductors or non-linear resistances. Examples are, diode valve, transistors, electrolyte, etc.

Illustration: A 5 V battery is connected to a 10 Omega resistance. Calculate the amount of current flowing through the circuit.

Solution: It is given that

V = 5 V

R = 10 Omega

To find I =?

According to Ohm's Law

V = IR

Rightarrow ;I= frac{V}{R}= frac{5}{10}= 0.5 ;A

Hence a current of 0.5 A flows through the circuit.

Sample Questions
(More Questions for each concept available in Login)
Question : 1

If 10 ampere current flowing through a wire, develops a potential difference of 50 volts across its ends, find the resistance of the wire.

Right Option : B
View Explanation
Explanation
Question : 2

Two resistors of resistance R_1; and; R_2 are connected in parallel to a battery of emf V. Write the following steps to determine the electric current flowing through the wire in proper sequence.

(A) Use the Ohm's law, V=IR.

(B) Determine the effective resistance (R_{eff}) of the parallel combination of resistors.

(C) Determine the electric current by using the relation,

I=frac{V}{R_{eff}}.

Right Option : C
View Explanation
Explanation
Question : 3

According to ohm's law, under given physical conditions

Right Option : D
View Explanation
Explanation
 
Video Link - Have a look !!!
 
Language - English
 
Chapters
Simple Harmonic Motion
Cytology
Classifucation Of Plants
Structural Composition Of Plants
Nutrition In Plants, Harmones And Plant Disease
Ecosystem
Classification In Animals
Nutrition In Animals
Human Digestive System
Human Respiratory System
Human Skeleton System
Human Excretory System
Human Nervous System
Human Circulatory System
Human Endocrine System
Human Reproductive System
Genetics
Human Diseases
States Of Matter
Metals And Non Metals
Acid Bases And Salts
Periodic Classification
Fuel, Combustion And Flame
Environmental Chemistry
Rest And Motion
Work Power And Energy
Gravitation
Pressure And Its Effects
Sound and Waves
Heat And Temperature
Light - Reflection
Electricity And Magnetism
Modern Physics
Force And The Laws Of Motion
Light - Refraction
Dispersion And Human Eye
Magnetic Effect Of Electric Current
Atom And Molecule
Pre-Historic Period
Indus Valley Civilization
Vedic Civilization
Religious Reform Movement
The Early Kingdoms
The Mauryan Empire
Post Mauryan Period
The Age Of The Guptas
Post Gupta Era
Age of Rajput
Khilji Dynasty
Slave Dynasty
Tughlaq and Sayyid Dynasty
Vijaynagar Empire And Bahamani Kingdom
Mughal Empire And Beyond
Lodhi Dynasty
Cholas, Chalukyas and Pallavas
Arab Invasions
Bhakti and Sufi Movement
Rise of Sikhs, Jats and Marathas
Administrative Structure of Delhi Sultanate
Architecture During Medivial India
Advent Of The Europeans
Post Mughal Period
Rise of New States in 18th Century
Growth of British Paramountacy
Socio Religious Reforms
Constitutional Development of India
Indian Struggle Against British Rule
The Revolt Of 1857
Education Under British Rule
Role of Press in Freedom Struggle
First Phase of National Movement
Second Phase of National Movement
Third Phase of National Movement
Constitutional Development in India
Constituent Assembly
Union And Its Territory
Structure of Indian Constitution
Fundamental Rights and Duties
The Union Executive
The Union Legislature
Constitutional Amendments and Provisions
Judiciary In India
Emergency Provisions
Center - State Relations
The State Executive
The State Legislature
Election Commission Of India
Constitutional Organisation
Non-Constitutional Organisation
Local Self Goverment
India - Size And Location
Geological History Of India
The Physical Features Of India
Climate Of India
Soils In India
Natural Vegetation
Windlife Conservation In India
Drainage System of India
Irrigation System Of India
Agriculture In India
Livestock And Fisheries In India
Minerals And Energy Resources In India
Means Of Transport In India
Major Industries In India
Tribes of India
Census of India 2011
Music
Dance
Theatre
Pantings
Art, Architecture & Culture of India
Bio-Diversity
Earth And Its Structure
Land Rock And Soil
Atmosphere, Climate And Weather
Oceanography
Human And Regional Geography
Economic Growth And Development
Sectors Of Indian Economy
Economic Planning Of India
Fiscal And Monetary Policy In India
Infrastructure In India
Effects Of British Rule On Indian Economy
National Income
Banking System In India
Poverty And Unemployment
Inflation And Trade Cycles
Major Institutions
Environmental Studies
Chemistry In Everyday Life
Units And Dimensions
Tissues In Organism
Content / Category
Class / Course
 
 
Related Videos
Language - Hindi/English
Language - English

Language - English
Language - Hindi/English

Language - English
Language - Hindi/English


Students / Parents Reviews [10]