Skip to content 
Electrical Resistance and Conductance
Here you can find the complete detail of the theory of electrical resistance and conductance which is useful for competitive exams and science students. We hope you would clear all your concept of electric resistance and conductance from the published post -Complete detail of electrical circuit resistance and conductance. The topic ‘Complete detail of electrical resistance and conductance is written by an expert. The electrical resistance is such a physical quantity that is always unwanted quantity in an electrical circuit but on the other hand, we utilize its great applications in our life.
Electrical resistance and conductance
The electric resistance of any substance is the physical property of a substance that opposes the flow of electric current, It was a German scientist Siemon George Ohm first observe this phenomenon of the matter and discovered Ohm’s law in 8 January 1926. He found the relationship between voltage and current. Conductance is also the physical property of matter which is the ease of flowing electric current means it is the ability of a matter to flow a charge in it.
You can also study related topics
Class 10 Physics Viva Voce Questions and Answers
Myopia, Hypermetropia and Presbyopia
Electrical resistance and conductance
Electric Current and Heating effect of Electric Current
What is a potential difference across an electric field ?
Why do the star twinkle but planets don’t
Light reflection, refraction, scattering, and dispersion
Electrical resistance and conductance
Electrical resistance
Ohm’s ‘law states that electric current is directly proportional to the potential difference between the ends of a conductor, the electric resistance is the physical property of the matter which opposes the flow of electric current. The unit of resistance is represented by the last letter (24 th) of Greek alphabet Ω uppercase omega named Ohm after the name of German Physicist George Simon Ohm.
V∝ I
V = IR
Where V is the voltage across a conductor and i is the electric current generated by the voltage across its ends. The electric resistance of conductors like silver, copper, aluminum, and iron is low, three of them, copper, aluminum, and iron are mostly used to build electric wire because silver is not found abundantly in the earth thereby costlier compared to rest of all the metals. All the matters which allow the flow of the electric current is known as the conductors. The resistance of the matter like plastic, air, soil etc is too higher to allow the flow of electric current so these matters are known as insulators.
NCERT Solutions Class 10 Science from chapter 1 to 16
The electric resistance in a circuit is required to control the electric current, the resistance of cables and wire is neglected when a net resistance of a circuit is calculated. The components that are used to control electric current are known as resistors,you would have seen the filament of an electric bulb made of spiral tungsten wire, tungsten is used in that because its resistance is higher, this higher resistance causes it to heat up enough to glow. The heating elements in the iron, toaster, electric pan, electric pressure cooker, electric shower, etc are bigger versions of the filaments. Have you observed how a voltage is controlled in a stabilizer or volume of a musical instrument or television, actually in all these cases we increase or decrease the electric resistance through a variable resistor attached with the volume knob.
The resistance of a conductor is directly proportional to the length of the conductors, you can get it through the example of a water pipe, the speed of water is slower in a pipe have more length compared to the pipe of the same radius but of shorter length.The flow of electrons in the wire and the flow of water in the water pipe can be supposed as the same idea.
R ∝ l …..(i)
The resistance of the conductor is inversely proportional to the cross-sectional area of the conductor. You can get it through the example of water flows slower in the thinner pipe compared to the wider pipe if both pipes are of the same length.
R ∝ 1/A
From (i) and (ii) we have
R = ρ. l/A
R= Resistance
l= length of the conductor
ρ = Specific resistance of the matter
It is that’s why the heater wire and tungsten wire is designed into the spiral shape of the coil so as to accommodate its sufficient length in the smaller area of the heater and bulb.
The combination of the resistance- The ways of connecting resistors are of two kinds.(i) Series connections (ii) Parallel connections
(i) Series connections- In the electric circuit when the positive terminal of one resistor is connected to the negative terminal of another resistor then such a combination of resistors is known as the series connections.
The net resistance of the circuit is the sum of magnitudes of all the resistors in series. In series connection, the voltage of the battery is distributed across each resistor in the proportion of their value ,as we know the length is directly proportional to the resistance, so to get the net resistance of the circuit all the individual resistances should be added.
RT = R1 + R2 + R3
Where RT is the total net resistance of the circuit
The Parallel Connection – When the positive terminal of all the resistors are connected to the positive terminal and the negative terminal of all the resistors are connected to the negative terminal of a battery, then such a combination of the circuit is known as a parallel connection. In parallel connection of resistors, the voltage across each resistor is the same but current drawn by each resistor is in proportion to their magnitude of the resistance.
As we know the resistance is inversely proportional to the area of cross-section of the conductor, hence the net resistance RT of parallel combinations of resistors is calculated as a sum of the reciprocal of their resistance.
1/RT = 1/R1 +/R2 +R3
RT = (R1 R2 R3 )/(R2 R3 +R3 R1 +R1 R2 )
Electrical resistance and conductance
Conductance
Conductance of the Circuit- The conductance(G)of the circuit is inverse of the resistance
G = 1/R
From Ohm’s law V = iR
R = V/I
G = I/V
The conductance of a substance is the ratio between the electric current and voltage, conductance is the ease with which an electric current passes through a substance, when voltage is constant across an electric component then conductance is directly proportional to the electric current flowing through it.
Unit of conductance is the inverse of Ohm i.e Mho or Siemen, if i =1A and voltage is 1 volt then one unit of conductance is 1 ampere/volt or 1 Mho or 1 Siemen or simply 1S.
Click for online shopping
Future Study Point.Deal: Cloths, Laptops, Computers, Mobiles, Shoes etc
Conductivity
As the conductance is inverse of resistance, on the same way the conductivity is inverse of resistivity.
The conductance of a given material depends on the following physical parameters
The conductance of a substance is inversely proportional to the length of the conductor and directly proportional to the area of the cross-section of the conductor, therefore it can be expressed in terms of the following formula
R = ρ. l/A
ρ = RA/l
σ = 1/ρ
σ = l/RA
R = l/σA
The unit of conductivity is
= (the unit of l)/[unit of R×unit of A)
=m/(Ωm²)
Unit of σ = m/Ωm2
= 1/Ωm = S/m [S=1/Ω,unit of conductance,i.e Siemen)
Unit of conductivity is Siemen/meter
The conductivity of few metals
| Metal | Resistivity | Conductivity |
| Silver | 1.50×10-8 | 6.30×107 |
| Copper | 2.44×10-8 | 4.10×107 |
| Gold | 1.68×10-8 | 1.68×107 |
| Aluminum | 2.82×10-8 | 3.5×107 |
| Iron | 1.0×10−7 | 1.00×107 |
| Calcium | 3.36×10−8 | 2.98×107 |
| Tungsten | 5.60×10−8 | 1.79×107 |
Study our post
Important Science Notes for Class 9 and 10 grade
Class 10 CBSE Science Notes
Human reproductive systems of Male & Family
Modes of reproduction used by single organisms-Asexual reproductions
The structure and anatomy of the Heart
Anatomy of the Human brain-Class 10 CBSE
NEET Sylabus and its preparation
Class 10 Biology Viva Voce Questions and Answers for CBSE Board 2020-21
Class 10 chemistry Viva Voce Questions and Answers
Class 10 Physics Viva Voce Questions and Answers
Class 10 Chemistry Practical Based Questions and Answers
What are the physical and chemical properties of metals?
Type of Chemical Reactions with Complete detail
Chemical properties of Acids and Bases-A note for grade 10 students
Trends in the property of element from left to right and up to down in the modern periodic table.
What is pH value and its importance in everyday life.
Ozone Layer and How it is Getting depleted.
Myopia, Hypermetropia and Presbyopia
Human eye structure and its function
Electrical resistance and conductance
Electric Current and Heating effect of Electric Current
What is a potential difference across an electric field ?
Difference between soaps and detergents
Why do the star twinkle but planets don’t
Light reflection, refraction, scattering, and dispersion
Extraction of metals as per the activity series
Ionic and covalent compounds and the difference between them
Food chain and food web in an ecosystem
Class 9 CBSE Science Notes
Evoporation,Vapourization and Latent heat -Class 9 CBSE notes
What is an atom,molecule and atomicity of a substance?
How to determine Valency,net charge of an ion and Molecular formula of a substance.
If energy is conserved then why do we need to save it for future generations?
Molar mass,molecular mass and mole concept
What is second law of of motion ?
How to evaluate recoil velocity of gun
Average Speed and Average Velocity: Differences
The universal law of gravitational force
Archimedes Principle: Complete detail
Thrust and Pressure : Difference
You can compensate us by donating any amount of money for our survival
Our Paytm NO 9891436286
NCERT Solutions of Science and Maths for Class 9,10,11 and 12
NCERT Solutions for class 9 maths
NCERT Solutions for class 9 science
CBSE Class 9-Question paper of science 2020 with solutions
CBSE Class 9-Sample paper of science
CBSE Class 9-Unsolved question paper of science 2019
NCERT Solutions for class 10 maths
CBSE Class 10-Question paper of maths 2021 with solutions
CBSE Class 10-Half yearly question paper of maths 2020 with solutions
CBSE Class 10 -Question paper of maths 2020 with solutions
CBSE Class 10-Question paper of maths 2019 with solutions
NCERT Solutions for Class 10 Science
Solutions of previous year’s science & maths question papers
Solutions of class 10 Science question paper 2019 CBSE
CBSE Class 10 science question paper 2020 SET -3 solutions
NCERT Solutions for class 11 maths
| Chapter 1-Sets | Chapter 9-Sequences and Series |
| Chapter 2- Relations and functions | Chapter 10- Straight Lines |
| Chapter 3- Trigonometry | Chapter 11-Conic Sections |
| Chapter 4-Principle of mathematical induction | Chapter 12-Introduction to three Dimensional Geometry |
| Chapter 5-Complex numbers | Chapter 13- Limits and Derivatives |
| Chapter 6- Linear Inequalities | Chapter 14-Mathematical Reasoning |
| Chapter 7- Permutations and Combinations | Chapter 15- Statistics |
| Chapter 8- Binomial Theorem | Chapter 16- Probability |
CBSE Class 11-Question paper of maths 2015
CBSE Class 11 – Second unit test of maths 2021 with solutions
NCERT solutions for class 12 maths
| Chapter 1-Relations and Functions | Chapter 9-Differential Equations |
| Chapter 2-Inverse Trigonometric Functions | Chapter 10-Vector Algebra |
| Chapter 3-Matrices | Chapter 11 – Three Dimensional Geometry |
| Chapter 4-Determinants | Chapter 12-Linear Programming |
| Chapter 5- Continuity and Differentiability | Chapter 13-Probability |
| Chapter 6- Application of Derivation | CBSE Class 12- Question paper of maths 2021 with solutions |
| Chapter 7- Integrals | |
| Chapter 8-Application of Integrals |
Class 12 Solutions of Maths Latest Sample Paper Published by CBSE for 2021-22 Term 2
Class 12 Maths Important Questions-Application of Integrals
Solutions of Class 12 Maths Question Paper of Preboard -2 Exam Term-2 CBSE Board 2021-22
Solutions of class 12 maths question paper 2021 preboard exam CBSE
