Need of small charge in definition of electric field?

In summary, the purpose of including a small charge in the definition of electric field is to measure the strength and direction of the field at a specific point. The value of the small charge does not affect the field, and a smaller charge is used to avoid altering the field. The strength of the electric field decreases as the distance from the small charge increases, and the small charge is typically defined as positive but the direction of the electric field can be positive or negative.
  • #1
Raj Batra
2
0
Why do we need infinitesimally small charge in definition of electric field? Since the test charge cannot exert force on itself, F on test charge will not change whatever the value of test charge q is. So, F/q will be same for any value of test charge. Then why do we need this limit of infinitesimally small charge?
 
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  • #2
A larger charge will influence the charge distribution in the environment, and therefore the field at its position.
 

Related to Need of small charge in definition of electric field?

1. What is the purpose of including a small charge in the definition of electric field?

The small charge is used to measure the strength and direction of the electric field at a given point in space. It acts as a test charge to calculate the force it experiences due to the surrounding electric field.

2. Can the small charge be of any value in the calculation of electric field?

Yes, the value of the small charge does not affect the strength or direction of the electric field. It is simply used as a reference point to measure the field.

3. Why is a small charge used instead of a larger one in the definition of electric field?

A small charge is used because it has a negligible effect on the electric field it is measuring. A larger charge would significantly alter the electric field and give inaccurate results.

4. How is the electric field strength affected by the distance from the small charge?

The strength of the electric field is inversely proportional to the square of the distance from the small charge. As the distance increases, the electric field strength decreases.

5. Is the small charge used in the definition of electric field always positive?

Yes, the small charge is typically defined as a positive charge. However, the direction of the electric field can be positive or negative, depending on the charge of the source that is creating the field.

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