Test charge, I think is the answer you are looking for.
positive charge
No, if two electric field lines are drawn at a point, this would meant two directions of electric field at that point which is impossible.
This is a matter of limits. If you are measuring the electric field at a point that is a distance off of an infinite sheet of charge the direction of the electric field will be perpendicular to the sheet due to the symmetry of the situation. We can think of the radius as the distance between a point on the sheet and the normal line to the sheet that passes through the point where the electric field is being considered. If we look at the addition to the electric field from the charge on the sheet as this radius approaches infinity the component of the electric field in the direction of the net electric field will approach 0.P.S. Drawing a diagram of the situation with arrows denoting the directions of force from different parts of the sheet can be very helpful in understanding.
Yes. An electric field is represented by electric field lines. Electric field lines are a visual representation of the strength and direction of an electric field in a region of space. In the vicinity of any charge, there is an electric field and the strength of the electric field is proportional to the force that a test charge would experience if placed at the point. (That is a matter of definition of electric field.) Mother nature produces electric fields, but humans can not see electric fields. Humans invented the idea of field lines to create a mental picture of the field. The two most common ways are to draw lines in space or to draw a collection of arrows in space. In the case of arrows, they are vector representations of the strength and direction of the electric field at the point in space where each arrow is drawn. Representing an electric field (and this works with other fields also) with lines is a sophisticated and time honored tradition. The density of lines in any region of space is proportional to the strength (magnitude) of the field in that region of space. The direction of the field is along the direction of the line at each position on each of the lines. In such a graphical representation the field direction goes out from positive charge and in towards negative charge and the visualization usually has some indication of the sign of charge or direction of the field to give the information about direction of the vector field represented by the field lines. There is a small caveat. It is not only charge that can produce electric fields. An electric field can be produced by a changing magnetic field. This is technologically important (since electric motors work on this principle) and scientifically fascinating, requiring a somewhat more sophisticated aspect of electromagnetic theory, but ultimately the electric field or electric flux can be visualized with lines (or arrows) in a manner exactly as is done for stationary charges.
The work done by you to turn the electric dipole end for end in a uniform electric field depends on the initial orientation of the dipole with respect to the field. If the dipole is initially oriented such that its positive and negative charges are parallel to the electric field, then no net work is done as the electric field does not do any work on the dipole as the electric field lines do not transfer any energy. On the other hand, if the dipole is initially oriented such that its positive and negative charges are perpendicular to the electric field, then work is done by you to turn the dipole as the electric field exerts a force on the charges in the dipole in opposite directions, causing them to move in opposite directions. As a result, you have to do work to move the charges and turn the dipole.
positive charge
No, if two electric field lines are drawn at a point, this would meant two directions of electric field at that point which is impossible.
This is a matter of limits. If you are measuring the electric field at a point that is a distance off of an infinite sheet of charge the direction of the electric field will be perpendicular to the sheet due to the symmetry of the situation. We can think of the radius as the distance between a point on the sheet and the normal line to the sheet that passes through the point where the electric field is being considered. If we look at the addition to the electric field from the charge on the sheet as this radius approaches infinity the component of the electric field in the direction of the net electric field will approach 0.P.S. Drawing a diagram of the situation with arrows denoting the directions of force from different parts of the sheet can be very helpful in understanding.
An electric field can be represented diagrammatically as a set of lines with arrows on, called electric field-lines, which fill space. Electric field-lines are drawn according to the following rules: The direction of the electric field is everywhere tangent to the field-lines, in the sense of the arrows on the lines. The magnitude of the field is proportional to the number of field-lines per unit area passing through a small surface normal to the lines. Thus, field-lines determine the magnitude, as well as the direction, of the electric field. In particular, the field is strong at points where the field-lines are closely spaced, and weak at points where they are far apart. Electric Field intensity It was stated that the electric field concept arose in an effort to explain action-at-a-distance forces. All charged objects create an electric field which extends outward into the space which surrounds it. The charge alters that space, causing any other charged object that enters the space to be affected by this field. The strength of the electric field is dependent upon how charged the object creating the field is and upon the distance of separation from the charged object. In this section of Lesson 4, we will investigate electric field from a numerical viewpoint - the electric field strength. An electric field can be represented diagrammatically as a set of lines with arrows on, called electric field-lines, which fill space. Electric field-lines are drawn according to the following rules: The direction of the electric field is everywhere tangent to the field-lines, in the sense of the arrows on the lines. The magnitude of the field is proportional to the number of field-lines per unit area passing through a small surface normal to the lines. Thus, field-lines determine the magnitude, as well as the direction, of the electric field. In particular, the field is strong at points where the field-lines are closely spaced, and weak at points where they are far apart. Electric Field intensity It was stated that the electric field concept arose in an effort to explain action-at-a-distance forces. All charged objects create an electric field which extends outward into the space which surrounds it. The charge alters that space, causing any other charged object that enters the space to be affected by this field. The strength of the electric field is dependent upon how charged the object creating the field is and upon the distance of separation from the charged object. In this section of Lesson 4, we will investigate electric field from a numerical viewpoint - the electric field strength.
Yes. An electric field is represented by electric field lines. Electric field lines are a visual representation of the strength and direction of an electric field in a region of space. In the vicinity of any charge, there is an electric field and the strength of the electric field is proportional to the force that a test charge would experience if placed at the point. (That is a matter of definition of electric field.) Mother nature produces electric fields, but humans can not see electric fields. Humans invented the idea of field lines to create a mental picture of the field. The two most common ways are to draw lines in space or to draw a collection of arrows in space. In the case of arrows, they are vector representations of the strength and direction of the electric field at the point in space where each arrow is drawn. Representing an electric field (and this works with other fields also) with lines is a sophisticated and time honored tradition. The density of lines in any region of space is proportional to the strength (magnitude) of the field in that region of space. The direction of the field is along the direction of the line at each position on each of the lines. In such a graphical representation the field direction goes out from positive charge and in towards negative charge and the visualization usually has some indication of the sign of charge or direction of the field to give the information about direction of the vector field represented by the field lines. There is a small caveat. It is not only charge that can produce electric fields. An electric field can be produced by a changing magnetic field. This is technologically important (since electric motors work on this principle) and scientifically fascinating, requiring a somewhat more sophisticated aspect of electromagnetic theory, but ultimately the electric field or electric flux can be visualized with lines (or arrows) in a manner exactly as is done for stationary charges.
The work done by you to turn the electric dipole end for end in a uniform electric field depends on the initial orientation of the dipole with respect to the field. If the dipole is initially oriented such that its positive and negative charges are parallel to the electric field, then no net work is done as the electric field does not do any work on the dipole as the electric field lines do not transfer any energy. On the other hand, if the dipole is initially oriented such that its positive and negative charges are perpendicular to the electric field, then work is done by you to turn the dipole as the electric field exerts a force on the charges in the dipole in opposite directions, causing them to move in opposite directions. As a result, you have to do work to move the charges and turn the dipole.
All of the lines, in the field are uniformly spaced, because the fartherapartthe lines are, the weaker the field is, but if the field is the same all around, then the lines are also the same, all around the field.
Yes. The electric field in physics is represented by a vector, it has three components governing the field strength in the up-down, left-right and forward-backwards directions.
Direction and electric flux density. Representing an electric field (and this works with other fields also) with lines is a sophisticated and time honored tradition. The density of lines in any region of space is proportional to the strength (magnitude) of the field in that region of space. The direction of the field is along the direction of the line at each position on each of the lines. In such a graphical representation the field direction goes out from positive charge and in towards negative charge and the visualization usually has some indication of the sign of charge or direction of the field to give the information about direction of the vector field represented by the field lines.
The net electric field inside a dielectric decreases due to polarization. The external electric field polarizes the dielectric and an electric field is produced due to this polarization. This internal electric field will be opposite to the external electric field and therefore the net electric field inside the dielectric will be less.
An electro-magnetic field is made up of both an electric and a magnetic field. And they both consist of photons. The two fields are orthogonal in direction. Which means their wave directions are perpendicular to each other. EMF's are produced each and every time the momenta of electrons changes. So when the speed, direction, or both of electrons change, EMF is created and the electric field is part of that EMF.
An electric field can be represented diagrammatically as a set of lines with arrows on, called electric field-lines, which fill space. Electric field-lines are drawn according to the following rules: The direction of the electric field is everywhere tangent to the field-lines, in the sense of the arrows on the lines. The magnitude of the field is proportional to the number of field-lines per unit area passing through a small surface normal to the lines. Thus, field-lines determine the magnitude, as well as the direction, of the electric field. In particular, the field is strong at points where the field-lines are closely spaced, and weak at points where they are far apart. Electric Field intensity It was stated that the electric field concept arose in an effort to explain action-at-a-distance forces. All charged objects create an electric field which extends outward into the space which surrounds it. The charge alters that space, causing any other charged object that enters the space to be affected by this field. The strength of the electric field is dependent upon how charged the object creating the field is and upon the distance of separation from the charged object. In this section of Lesson 4, we will investigate electric field from a numerical viewpoint - the electric field strength. An electric field can be represented diagrammatically as a set of lines with arrows on, called electric field-lines, which fill space. Electric field-lines are drawn according to the following rules: The direction of the electric field is everywhere tangent to the field-lines, in the sense of the arrows on the lines. The magnitude of the field is proportional to the number of field-lines per unit area passing through a small surface normal to the lines. Thus, field-lines determine the magnitude, as well as the direction, of the electric field. In particular, the field is strong at points where the field-lines are closely spaced, and weak at points where they are far apart. Electric Field intensity It was stated that the electric field concept arose in an effort to explain action-at-a-distance forces. All charged objects create an electric field which extends outward into the space which surrounds it. The charge alters that space, causing any other charged object that enters the space to be affected by this field. The strength of the electric field is dependent upon how charged the object creating the field is and upon the distance of separation from the charged object. In this section of Lesson 4, we will investigate electric field from a numerical viewpoint - the electric field strength.