[Physics Class Notes] on Unit of Conductivity Pdf for Exam

Physics is the branch of science that deals with the structure of matter, studying the planets to know how things actually work and finding out how the fundamental constituents of the universe interact. It studies objects starting from the very small using quantum Physics to the whole universe using the general theory of relativity. It is the physical processes and phenomena of a particular system and the physical properties and composition of any matter that is found.

Physics is also an international enterprise, which plays a key role in the future progress of humankind by studying how the universe is actually working. Physics contributes to the technological infrastructure and provides trained personnel to the universe, necessary to capitalize on scientific advances and discoveries in our future.

In general, a measure of the power of how well a given substance can conduct electric current, adequate to the reciprocal of the resistance of the substance, is framed as the term Conductivity. The Conductivity or any sort of specific conductance of an electrolyte solution may be a measure of its ability to produce the required amount of electricity. The ability of a solution of an electrolyte to conduct electricity due to the free ions of the electrolyte that is no longer bound in the lattice is called the Conductivity or specific conductance of that electrolyte’s solution. 

The SI unit of Conductivity is Siemens per meter (S/m).

The Conductivity of any substance is its capacity to transfer electricity through ions. It can be of different variations, such as ionic, thermal or electrical. The electrical Conductivity Unit measures the current flow through an electrolyte solution.

The SI Unit of Conductivity measures the frequency at which a current or heat passes through any object. The universal measure for conductance is Siemens for per meter or S/m for any substance. It is also equal to ohm^-1*m^-1 when heat waves or thermal energy flows through a material.

It is also represented through the Greek letter σ. Its formula is:

σ = 1/ρ

Where σ = reciprocal of resistivity, while ρ = resistivity of an object.

Electrical Conductivity occurs when a current flows in response to the forces acting upon them in an electric field. It is a measure of the amount of electrically charged particles that a material can transfer. The electronic conduction that flows through most particles depends on the number of electrons present in an object. 

Metals are an excellent conductor of electricity because they contain a large number of free electrons that can carry current within that material.

Fun Fact: Silver is the most conductive among all other metals, followed by copper and gold.

The SI Unit of electrical Conductivity, is defined as its ratio between current density (J) and intensity for an electric field (e).

S = J/e

Similarly, in water, conduction occurs through a free flow of ions. Though pure water does not help in conducting an electric current, distilled water and seawater allows conduction via electronically charged ions. This phenomena occurs due to the presence of minerals in distilled water and seawater. With an increase in the condensation of ions, there is an increase in Conductivity.

 

Resistance and Conductivity Relationship

Resistance is a material property that restricts the flow of electrons in it. Consider a situation where there is a tunnel and water. Easier the water flows through a tunnel, the lower Resistance it contains.

However, Conductivity enables a free flow of electronically charged particles quickly through a material. The SI unit of Conductivity is precisely the reverse of the SI unit of Resistance. 

The formula of Resistance is: R = ρ*l/A

Where ρ = resistivity.

A = cross section area

L = length of a wire

R = wide Resistance

However, there is a link between Conductivity and Resistance. A good conductor is any material that offers little Resistance when electricity flows through it. If a substance has less resistivity to thermal energy or heat, it implies that it has great conduction or vice versa.

 

Multiple Choice Questions

Here are some solved questions on the SI unit of conductivity. Read them and expand your knowledge.

1. Conductivity is an Object’s Ability to Transmit 

a. Current

b. Voltage

c. Resistance

d. All the above points

Ans: a

 

2. Which Reagent has a Specific Conductance?

a. HCl

b. Potassium chloride

c. Sodium chloride

d. Magnesium chloride

Ans: b

 

3. The Universally Recognised SI Unit of Electric Conductance is

a. Ohm

b. Watt

c. Siemens

d. Joule

Ans: c

 

4. Which of the Following Objects have a High Conductance?

a. Plastic

b. Water

c. Glass

d. Copper

Ans: d

 

5. The Reverse of Conductivity is
a. Resistivity

b. Turbidity

c. Viscosity

d. None of these

Ans: a

The field of conductivity is vast and understanding what is the unit of conductivity requires in-depth knowledge. You can now download our app to access detailed study material, as well as online classes to understand these concepts in detail.