ELECTRIC FIELD LINES
We know that every charge particles create a electric field around themselves, whether it is positive charge or negative charge.
But have you ever seen the electric field around any charge particle, absolutely not. But you have must observed or experience it in daily life. e.g –
When we bring a small charge body near a other charged body then it show attraction or repulsion according to the nature of the charged body.
This attraction and repulsion shows that these charged bodies have electric field around them which exerts electrical force during interaction. And if there is no electric field then there is no electric force. So electric field is essential for exerting electrical forces.
However, we cannot see the electric field of any charged body because they are invisible, so this was the major problem for the contemporary physicists that how will they demonstrate it in text books or in their research papers.
And finally this problem was solved by the English physicist Michael Faraday, who give the pictorial representation of electric field, which helps the peoples to understand and analysis the behaviour of electric field in easier way.
In the pictorial representation which was given by the Michael Faraday, it is said that the electric field is composed of electric field lines.
Michael Faraday draw a imaginary line called electric line of force or electric field lines to visualise the electric field around any charge particle.
In this section we will discuss about electric field lines in details, so stay connected with us till end.
ELECTRIC FIELD LINES
Electric field lines or electric lines of force is a hypothetical lines or curve which are drawn by the Michael Faraday to visualise the electric field around any charge particle.
Electric field lines gives the direction of the electric field when the tangent is drawn at its point. Electric field lines form the three dimensionally region around the charge particle.
For positive charges electric field lines start from it and ends to the infinity or into the negative charges. For negative charges electric field lines comes radially inward from the infinity or from the positive charge.
ORIGIN OF ELECTRIC FIELD LINES
To understand the origin of electric field lines, we have to perform an experiment.
Take a unit positive charge as a source charge and –
1). BRING A UNIT POSITIVE TEST CHARGE
When you a bring a unit positive test charge near the source charge then according to the Coulomb’s Law, they start exerting forces to each other. The test charge feel some push from the source charge.
This push show that the direction of their electric field are the same i.e both charges have electric field radially outward. These both radially outward oriented electric field interact and exert repulsive force on each other.
So from this experiment we can conclude that in every positive charge particles, electric field lines start from the source and ends to the infinity. i.e radially outward.
2). BRING A UNIT NEGATIVE TEST CHARGE
When you bring a unit negative test charge near to the source charge then it also exert electrical force according to the Coulomb’s Law.
If we saw carefully then we will find that negative charge particle slightly get tilted towards the source charge. Means source charge is pulling the negative test charge. This pulling show that the direction of their electric field are not same. If one is radially outward then other is radially inward.
Means when we keep two opposite charge particles at some distance apart, then the electric field lines originate from the source charge and enter to the negative test charge.
PROPERTIES OF ELECTRIC FIELD LINES
Here we are going to mention some basic properties regarding to the electric field lines.
1). Electric field lines starts from the positive charge and end at the negative charge. In the case of single charge, electric field lines may start and end to the infinity.
2). Tangent to any point on the electric field lines gives the direction of the electric field at that point.
3). Two field lines can never be intersect with each other, it is because if they intersect then two tangent can be drawn from that point of intersection and show two direction of electric field at that single point which is not possible.
4). Electric field lines is continuous curve without any break.
5). Electric field lines do not form close loop because of conservative nature of electric field.
6). The originated electric field lines are perpendicular to the surface of the charged bodies.
7). Electric lines of force contract lengthwise to show the attraction between the two unlike charges.
8). The electric field lines of two like charges exert side wise pressure to show the repulsion between them and this makes field lines distorted.
9). If field lines are closely packed then it means electric field is stronger. If it is rarely packed then electric field is weaker.
10). Electric field lines do not pass through the conductor. The interior of the conductor is free from the influence of electric field.
SIGNIFICANCE OF ELECTRIC FIELD LINES
We have already discussed above that if field lines is closely packed then electric field is stronger and if it is rarely packed then electric field is weaker. But imagine, what if there is no electric field lines to visualise the electric field.
What if Michael Faraday didn’t give the pictorial representation of electric field.
We can’t see electric field with our naked eyes, then without knowing electric field lines how can we tell where is the stronger electric field and where is the rarer electric field.
Without knowing the electric field lines, how can we explain the mechanism of force between the two stationary like or unlike charges particles.
Electric field lines helps us a lot to understand the behaviour and nature of electric field in detail.
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