The strength and direction of the electric field at the position indicated by the dot in the figure are indicated by arrows.
The electric field strength at this depth is approximately 0.9 V/m and does not change with time.
It is pointing in the direction perpendicular to our page, which means that it is a uniform magnetic field.
The strength of this magnetic field will be stronger near a current-carrying wire and weaker near a neutral wire or conductor without current flow across it.
The answer is discussed here about what is the strength of the electric field at the position indicated by the dot in (figure 1)?
Electric fields are often measured in volts per meter (V/m). This is simply because it’s easier to work with units of electricity before making any calculations involving physical measurements like meters, radians, degrees etc. This can be done by dividing the voltage (V) by the distance (m).
Here are some points discussed about the strength and direction of the electric field at the position indicated by the dot in the figure-
1. Strength of the electric field at this depth is approximately 0.9 V/m.
Electric field at depth is defined by the equation:
Where, E is electric field, V is voltage, d is distance of the depth measured from the point where a normal line is drawn perpendicular to the line of current i.e. to the wire carrying current. ‘d’ may be taken as distance between two terminals.
This depth can also be termed as depth of penetration (dp) or skin depth (ds) because it represents the depth at which an electric field has reduced to 1/e of the value at its source or surface.
The electric field at the surface of a conductor or in the immediate vicinity of a current-carrying wire has a value of E = V/d. The strength of the electric field is same everywhere and it does not change with time.
2. The electric field equals the voltage V divided by distance d, E=V/d.
Electric field is a vector quantity (composed of two scalars), it requires two numbers to calculate it. The direction is indicated by an arrow as well as magnitude. It is a vector field. The direction of the electric field is perpendicular to surfaces with respect to the position of the source of electric force (like point charge Q) .
From this position, an arrow is drawn to show the direction of the field.
In situations like this, there are many ways to find what direction an arrow should point; one useful way is to use the right-hand rule.
According to the right-hand rule, if you curl your fingers around the positive charge in a certain way and your thumb points in a certain direction, then that’s how your pencil would point if you put it on that plane and drew lines in the same direction as your thumb.
3. The electric field is uniform at all locations.
The electric field has the same value at all locations. This is because the surface of a conductor or in the immediate vicinity of a current-carrying wire is equipotential (i.e. everywhere on it has the same potential).
However, there would be differences in electric field if we consider different locations where a conducting sphere is carrying a point charge i.e. charge density varies from one point to another point on the surface of the sphere.
Electric field is the force per unit volume that arises between any two points in a uniform electric field. All points of a conducting sphere where charge density is uniform have E = 0. It is measured in volts per meter (V/m).
4. The electric field is the same at all points along any closed loop of conducting material.
Compared to open space, the magnitude of electric field is smaller inside conducting material than when that conductor is in open space.
However, the direction of the electric field remains the same everywhere in a conductor as shown in figure.
For example: if we take a loop of wire, you could cut it in two and pull it apart into two parts, one part parallel to the other. The same current will flow through both halves because they form a continuous conducting path. But there will be some force on each half because it has a magnetic field of its own.
