Electric Field

Key Concepts

• Electric field
• Field lines
• Fieldline due to charge

Introduction: 

Electric field 

Consider a charge present in a space that experiences either an attractive or a repulsive force.   

Why is there a force? 

It is due to the presence of an electric field.  

Electric field is defined as the electric property present in a particular space or area. The charge may be of any form, positive or negative, regular or irregular, but the electric property present in the particle is called the electric field.  

The strength of the electric field E should be defined for any charge. The electric field strength can be calculated by knowing the force which is exerted on the charge in the electric field and the charge value itself or unit charge.  

Therefore, E= F/q. 

Field lines: 

The electric field line is a visual representation of the electric field. 

Consider a charge present in the electric field line drawn to a particular charge, and the direction of the electric field line is a tangent to that electric field line. There may be any number of electric field lines, but no field lines intersect with each other. 

Field lines defines the intensity and direction of an electric field.The number of lines present in the area gives the electric field strength, and the tangent to the field line gives the direction of the field.  

Important points to remember in field lines: 

1. The field lines give the visual representation of the electric field.  

2. Field lines never intersect with each other. 

3. The number of field lines gives the field strength. The more the field lines, the more the strength. 

4. The tangent to the field line gives the direction of the field.  

5. Field line are perpendicular to the surface of the charge.  

Do it yourself: 

Rules to draw the field line:  

1. The field lines start at the charge and go on until it returns to the charge or moves to infinity. 

2. A stronger field has field lines close to each other. 

3. Depending on the charge, the number of field lines is defined. 

4. The direction of the electric field is the tangent to that electric field line. 

5. Electric field line never intersects. 

Field lines due to a positive charge: 

Consider a charge present in the space and the charge is positive, 

As the charge has the electric property, the field lines of the positive charge are going away from the charge to the infinity, and the field line is directed outward or away from the charge.  

The tangent of the field line drawn always shows away from the charge. 

Field lines due to a negative charge: 

Consider a charge present in the space and the charge is negative. 

As the charge has the electric property, the field lines of the negative charge are directed towards the charge itself, and the field line is directed inward or towards the charge.  

The tangent of the field line drawn always shows towards the charge. 

Summary

Electric field

The electric field is defined as the electric property of a particle present in a particular space or area. The charge may be of any form, positive or negative, regular or irregular, but the electric property present in the particle is called the electric field.
Field lines:
The electric field line is a visual representation of the electric field.
Important points to remember in field lines:
The field lines are a visual representation of the electric field.
Field lines never intersect with each other.
The number of field lines give the field strength of the field. The more the line, the more strength.
The tangent to the field line gives the direction of the field.
Field lines are perpendicular to the surface of the charge.

Rules to draw the field line:
Field lines start at the charge and go on until it returns to the charge or moves to infinity.
A stronger field has field lines close to each other.
Depending on the charge, the number of field lines is defined.
The direction of the electric field is a tangent to that electric field line.
Electric field line never intersect.
Field lines due to a positive charge:
As the charge has electric property, the field lines of a positive charge are always drawn away from the charge to the infinity, and the field line are directed outward or away from the charge.
Field lines due to a negative charge:
As the charge has electric property, field lines of a negative charge are always directed towards the charge itself, and the field line are directed inward or towards the charge.