# Surface Charge Density Formula

## Surface Charge Density Formula

The Surface Charge Density Formula is an important part of the Physics curriculum, and students learn about it in multiple classes at various levels of detail. This topic is critical for understanding many other concepts in the subject and discipline. Students can study the topic of Surface Charge Density Formula with the help of textbooks provided by educational boards. Depending on the class, these textbooks go over the Surface Charge Density Formula in great detail. Students in higher classes may struggle to understand the Surface Charge Density Formula for a variety of reasons.

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The majority of the Surface Charge Density Formula questions are equation-based, and they must be understood before they can be solved. The Extramarks platform can help you better understand the topic of Surface Charge Density Formula. Students have a variety of learning options. Those looking for an interactive learning experience can use the audiovisual modules for Surface Charge Density Formula. Students who prefer traditional learning methods can use the sample papers, chapter notes, and revision notes. Experts from across the country curate all of these study materials. This makes the study guides trustworthy, and students can use them to supplement their learning from textbooks.

### What is surface charge density?

Charge density is a measurement of the accumulation of electric charge in a specific field. It calculates the amount of electric charge based on the dimensions provided. The dimensions of an electric body can be its length, area, or volume.

Thus, charge density can be classified into three types. As a result, charge density is a measure of electric charge per unit volume of space in one, two, or three dimensions, according to electromagnetism. As a result, there are three types of these:

(i) Linear charge density per unit length, where q is the charge and is the length over which it is distributed. Coulomb m1 will be the SI unit.

(ii) Surface charge density per unit surface area, where q is the charge and A is the surface area. Coulomb m2 is the SI unit.

(iii) Volume charge density per unit volume, where q is the charge and V is the volume of distribution. Coulomb m3 is the SI unit. The amount of electric charge per unit surface area, in particular, is critical.

Surface charge describes the electric potential difference between the inner and outer surfaces of an object in different states. Surface charge density exists only on conducting surfaces and describes the total amount of charge per unit area.

The charge density describes the amount of electric charge that accumulates in a specific field. It primarily calculates the charge density per unit volume, surface area, and length. It calculates the amount of electric charge per square metre of space. This area could be one, two, or three dimensions. Charge density is affected by position, which can be negative.

### The formula for Surface Charge Density

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Surface charge density is computed as:

σ=qA

Where,

σ Surface charge density

q Electric Charge

A Surface area

The SI unit of Charge density is Coulomb per unit measurement under consideration.

### Solved Examples

Q.1: A long thin rod circular of length 50 cm and radius 7 sm has a total charge of 5 mC, which is uniformly distributed over it. Find the Surface charge density.

Solution:

Given parameters are:

q  = 5 mC = 5×10−3

Length of the rod i.e. l = 50 cm = 0.5 m

Radius of the rod = 7 cm

Thus the surface area of circulkar rod of cylinder shape, will be:

Surface Area of cylinder = 2×π×r×h

= 2×227×7×50

= 2200 sq cm = 0.22 sq m

The charge density formula computed for length is given by:

σ=qA

= 5×10−30.22

= 2.27×10−2

Surface charge density for the rod 2.27×10−2Cperm2