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Use these results and symmetry to find the electric field at as many points as possible without additional calculation. 8 x 10 –29C m 37. 2)2 , pointing towards the left. The two point charges are created by drawing a dipole conﬁguration with conductive silver ink on a sheet of black conductive paper. Make a qualitative sketch of the electric ﬁeld lines produced by four charges +q,−q,+q,−q, arranged clockwise on the four corners of a square with sides of length d. The two plates are given each given an equal magnitude of charge Q, but with opposite polarities, so a constant electric field E exists between the plates. The distance r is A) 0. 80m , and a second point charge q2=+6. The force at 3. A negative charge has a force in the opposite direction to the electric field. 2 x 10-19 C and -3. If the charges are separated by 20cm, what is the magnitude of the electric field halfway between the charges? My textbook says that the formula for electric. Electric Field. ! r F =q r E (1) where F is the force exerted on the charged particle, q is the charge of the particle and E is the electric field. (d) The particle could be momentarily at rest. The charge in the top drawing is a +2 µC charge and that in the bottom is –5 µC. (a) What is the direction of the electric field E? (b) How much torque would the dipole experience in this field? [2010C D] Sol. Use an E-field sensor to probe the electric field around the two charges. Since the electric eld has both magnitude and direction, it is a vector. 2 a) Find the electric field (magnitude and direction) a distance z above the midpoint between two equal charges q a distance d apart. 0 × 10–8 C halfway between the first two point charges experiences a force of magnitude. 1 Which law to use Apply Coulomb's law: where is the distance between the two charges. 8 * 10^(-6) C/m, and the second -2. Calculate : (i) The distance, d, between the two charges, (ii) The force between the two charges if they are moved to a distance = 3d apart. on the right has a uniform charge density −σ. So each charge is contributing eight newtons per coulomb of electric field at this point which means that the total net electric field would just be 16 newtons per coulomb at that point. This is Coulomb's Law for the Electric Fieldin conceptual form. 2 Field lines for an electric dipole. On which side of this charge-top, bottom, left, or right-is the electric field the strongest?. Thus, the electric field at any point along this line must also be aligned along the -axis. In that region, the fields from each charge are in the same direction, and so their strengths add. Electric Fields. 528 CHAPTER 17 Electric Charge and Electric Field An ion is an atom that has lost or gained one or more electrons. The relationship between electricity and magnetism is called electromagnetism. UNIT G485 Module 1 5. Use an E-field sensor to probe the electric field around the two charges. As the distance between two opposite magnetic poles increases, the flux density midway between them. The Indiana product has been a solid back during his career in Atlanta and thrived under then-offensive coordinator Kyle Shanahan's direction in 2016 season. The distance r is A) 0. Electric Charges and Fields Important Questions for CBSE Class 12 Physics Gauss’s Law. 2 a) Find the electric field (magnitude and direction) a distance z above the midpoint between two equal charges q a distance d apart. If a positive charge is put at that point, it will be pushed in. Therefore the electric potential will decrease when we move in the field direction. 6 x 10 ‐19 C m (2) 161. 6 x 10-19 Coulombs Experiments have shown that Like signed charges repel each other Unlike signed charges attract each other For an isolated system, the net charge of the system remains constant Charge. Calculate the distance from charge q 1 to the points on the line segment joining the two charges where the electric field is zero. 0 ×10-6 C and mass m. At what point along the line connecting the two charges is the net electric field due to the two charges equal to zero? Solution. We have looked at Coulomb's Law, the definition of the electric field, and applied that to find the electric field due to a point charge. The first line has charge density 4. The Coulomb law is: The magnitude of the electrostatic force between two points electric charges is directly proportional to the product of the magnitude of each charge and inversely proportional. 0 x 10 5 N/C. When this principle is logically extended to the movement of charge within an electric field, the relationship between work, energy and the direction that a charge moves becomes more obvious. If you have an electric field in some region, that will cause a change in. x-axis as shown at right and create an electric field in the space around them. general equestion. 18 X10 7 N/C d. What is the E field you see due to that charge? It's just E = k * (-20 µC) / (0. The resultant electric field of two parallel plates is double that of one sheet with the same charge: or. The Electric Field I: Discrete Charge Distributions 1999 because it corresponds to a position to the right of the 2. It is used to determine the extent to which surrounding charges generate a force. From above: Electric Field Strength in the space between two oppositely charged parallel plates. Think of the positive charge as being along the positive x-axis and the negative charge on the negative x-axis. B) Somewhere to the left of the +4q charge. Explains how to calculate the electric field between two charges and the acceleration of a charge in the electric field. (b) shows the electric field of two unlike charges. Since electric field is a vector quantity, it can be represented by a vector arrow. Consider two parallel sheets of charge A and B with surface density of σ and -σ respectively. The first line has charge density 4. 0 m C, are separated by a distance of 0. equipotential surfaces and the electric field lines look like for these two charge distributions. 28 A dipole with its charge -q and + q, located at the points (0, -b, 0) and (0, +b, 0), is present in a uniform electric field E. There exists some potential difference between these two points and If a charge'q' is placed at point B and move it to A, some amount of work will have to be done. at a point between two charges. The figure shows two different ways to visualize an electric field. ¨ A charge of 15. In conjunction with purely electric drive too, the tried-and-tested design principle of the suspension – with single-joint spring strut at the front, a multilink rear axle that is unique within the competitive field and electromechanical steering – guarantees maximum ride stability, steering precision and spontaneity when changing direction. The limits of these fields must also be different as the sources shrink to zero size. 0 * 106 J (N/C) How to solve: Put yourself at the middle point. Moreover, every single charge generates its own electric field. on the right has a uniform charge density −σ. field due to a point charge to approximate the electric field at x = 250 m. 20 (each has a magnitude F = qE) Thus, the net force on the dipole is zero. Two point charges are separated by a distance of 10. 0 ìC charge and a +6. (a) Determine the direction and magnitude of the electric field at a point P between the two charges that is 2. The electric field is radially outward from a positive charge and radially in toward a negative point charge. The Electric Field I: Discrete Charge Distributions 2001 (b) The particle is accelerating in the direction of r E. What is the direction and magnitude of electric field at A due to the two charges? Ans: E=45×〖10〗^3 NC^(-1) θ=36. Activity 1 The pictures below show the electric field lines of two different point charges: one positive, one negative. The capacitor is charged to provide a uniform electric field E of 105 V/m in the direction shown. 5 × 10 −7 × 0. The field is stronger between the charges. by cancelling out q (charge) on both. DEVELOP Coulomb’s law (Equation 20. 5 cm from the positive charge. The magnetic force between the two wires is repulsive. 1 Electric Charge There are two types of observed electric charge, which we designate as positive and negative. (a) Is the net electric field at a location halfway between the two charges (1) directed toward the charge, (2) zero, or (3) directed toward the 5. The direction of the force is along the line between the two charges. This is the force per unit charge. a source charge) causes an electric fieldto exist in the region of space arounditself. We can see from the following diagram that the net electric field at point P is due to the combined effects of both charges. The SI unit of electric field strength is newtons per coulomb (N/C) or. In Figure 5, the electric field between the infinite parallel plates is constant, so the work done by the field to move a charge from equipotential line 1 to line 2 is the same as the work to move the charge between line 2 and 3 or 3 and 4 or any two other equally spaced lines since the field, and thus the force, is constant. 528 CHAPTER 17 Electric Charge and Electric Field An ion is an atom that has lost or gained one or more electrons. It must be remembered that the electric force acts along the line of the electric field direction while the magnetic force acts at right angles to the field direction. electric field produced by the particles equal to zero? Answer: −0. 0 ìC charge is 4. The direction of the magnetic field i. This is the force per unit charge. Which arrow best represents the direction of their resultant electric field at point P? 11. (e) The force on the particle is opposite the direction of r E. In that experiment, a small charged drop of oil is observed in a closed chamber between two. Draw and label the electric field lines (at least eight of them) - you should include some near the edges of the parallel plates. The electric field of a dipole is proportional to the product of the magnitude of one of the charges and the distance between the charges (called the dipole moment). One is required to describe the other. Page 3 Which diagram best illustrates the electric field between charges A and B? (B) (C) (D) (B) (C) (D) The diagram below represents the electric field lines in the vicinity of two isolated electrical charges, A and B. 9 \mu C charge. Common SI units of electricity include the ampere (A) for current, coulomb (C) for electric charge, volt (V) for potential difference, ohm (Ω) for resistance, and watt (W) for power. electric force on the third charge due to the other two charges is zero. The other two Maxwell's equations, discussed below, are for integrals of electric and magnetic fields around closed curves (taking the component of the field pointing along the curve). Sketch the electric field lines in the vicinity of two opposite charges, where the negative charge is three times greater in magnitude than the positive. The charge on the right sphere is 3 times as large as the charge on the left sphere. Electrically Charged Particles Repel or Attract Each Other. The magnitude of the electric field between charges q2 and q3 has the same magnitude as the electric field produced by all three charges, so it is greater than that found in part (a). Describe the direction of the electric force between two opposite charges, between two like charges, and when a charge is in an electric field. What is the magnitude and direction of the electric field at a point midway between a -8. If you throw a charge into a uniform electric field (same magnitude and direction everywhere), it would also follow a parabolic path. Further, if there are two such sources in proximity of each. In other words, the electric field is the surrounding charges which create an electric field around a given point. For part b, you can see from part a that the electric field is not uniform (same magnitude and direction) as you move from the origin towards the second charge. The presence and strength of a magnetic field is denoted by "magnetic flux lines". 9:1, like a point charge 13. Electric Field on Earth. 035^2 2 + [1/4πεo] -11 μ / 0. The electric field E produced by charge Q 2 is a vector. ) Part A What is the magnitude of the electric force between the two charges? Hint A. For example, choose two equipotential lines, one at 10 V and 0. 2 a) Find the electric field (magnitude and direction) a distance z above the midpoint between two equal charges q a distance d apart. What are the magnitude and direction of the Electric Field E at the point midway between the charges?. What is the magnitude and direction of the electric field at point A, 0. Charge q 2 produces an E-field pointing upward (+y) while charge q 1 produces an E-field pointing into the 1 st quadrant. constant in physics. B) Somewhere to the left of the +4q charge. between charged parallel plates : Field (E) =v/d potential difference betwen the plates , d - the separation of the plates. •The direction the magnetic field produced by a moving charge is perpendicular to the direction of motion. Moreover, every single charge generates its own electric field. Electric field lines reveal information about the direction (and the strength) of an electric field within a region of space. Unlock Content. 0 µC charge 3. Some typical electric field strengths are shown in Table 1. 0 m C and q 2 = + 4. Draw a figure for it. In this case, the speed of the particle remains constant. he electric field is zero everywhere except in the gray region. C) Somewhere to the right of the −2q charge. 21-5 Coulomb’s Law Phys102 Lecture 2 - 2 Experiment shows that the electric force between two charges is proportional to the product of the charges and inversely proportional to the distance between them. One has a charge of -25 μC and the other +50 μC. The Coulomb law is: The magnitude of the electrostatic force between two points electric charges is directly proportional to the product of the magnitude of each charge and inversely proportional. Dust or impurities (any object) in the air may cause the air to break down more easily in one direction, giving a better chance that the step leader will reach the earth faster in that direction. Any charged particle has an electric field associated with it. Two identical positive charges of +Q are 1 m apart. The electric field near two charges. C) No, a zero electric field cannot exist between the two charges. Each moving charge is like a small element of electric current. The diagram below shows the location and charge of two identical small spheres. The direction at a particular point on a curved line is the direction of the Resultant vector of the fields of the two charges at the point. the nonvanishing field components in the case of opposite and equal charges. electric dipoles. The electric force on a positive charge in an electric field is in the direction of E, while; The electric force on a negative charge is opposite to the. Electric field strength is directly proportional to the force exerted on a positive test charge. Electric Field Intensity. 0 µC and a +6. (a) Is the net electric field at a location halfway between the two charges (1) directed toward the charge, (2) zero, or (3) directed toward the 5. Snapshot 2: the field of a charge-dipole interaction. Dipole Charge: One positive and one negative charge. In that region, the fields from each charge are in the same direction, and so their strengths add. Electric field lines point in the direction in which a positive test charge would respond to the electrostatic force; that is, away from positive charges and towards negative charges. It follows that the origin () lies halfway between the two charges. Electric field near a negative charge is directed radially into the charge as shown Electric field near a positive charge is directed radially out from the charge - Electric Field Electric field lines show • direction of the force • indicate its relative magnitude Similar to gravitational field lines 2+ Electric field lines Double the charge. 10 nC charge is located at point A (0, 6cm). Which one of the following statements is correct? A€€€€€ No energy is transferred when the movement is parallel to the direction of the field. We can call the influence of this force on surroundings as electric field. Figure 5b shows the electric field of two unlike charges. The physics of electric field between two charges. 0 x 10-7 C but opposite signs are held 15 cm apart. Which arrow best represents the direction of their resultant electric field at point P? 11. 0 mm on the axis? (b) If, instead, a particle of charge +4q 1 is placed at the location, what is the direction (relative to the positive direction of the x axis) of the net electric field at x = 2. This direction, it turns out, will always be perpendicular to the equipotential surfaces. 2 x 10-5 N on each other when they are at a distance, d apart. Two point charges are 10. There is a powerful flow of electric charge going through the battery, yet no individual electrons flow through the battery at all. Two point charges are located along the x axis: q 1 = +6. they are produced only by moving charges while electric fields are produced by both moving charges and stationary charges. 5 × 10 −8 C m along positive z-axis. The charge in the top drawing is a +2 µC charge and that in the bottom is -5 µC. a source charge) causes an electric fieldto exist in the region of space arounditself. (d) The particle could be momentarily at rest. (OpenStax 18. General Physics (PHY 2140) Lecture II Determine the magnitude and/or the direction as needed. 21-5 Coulomb’s Law Phys102 Lecture 2 - 2 Experiment shows that the electric force between two charges is proportional to the product of the charges and inversely proportional to the distance between them. If a charge of -2. During the years 1909 to 1913, R. constant in physics. The direction of the electric field is the direction in which a positive charge placed at that position will move. Find a symbolic expression for the resultant electric field at the center of the circle. Find a point C on AB such that electric field is zero at C. Electric Forces and Electric Fields CLICKER QUESTIONS Question L1. So the force will be accelerating the electron. The diagrams show four possible orientations of an electric dipole in a uniform electric field, E. The field of two unlike charges is weak at large distances, because the fields of the individual charges are in opposite directions and so their strengths subtract. 8 for a similar situation). 0 cm to the left of the +6. g What is a possible direction (a-g) of the electric field in the region where the field is non-zero?. 1-3, and the integral is taken round the whole loop. Charge + Plane: A charge near a grounded conductor. What are the magnitude and direction of the Electric Field E at the point midway between the charges?. Electric Field Line Patterns Two equal but like point charges At a great distance from the charges, the field would be approximately that of a single charge of 2q The bulging out of the field lines between the charges indicates the repulsion between the charges The low field lines between the charges indicates a weak field in this region. Point charges can be protons, electrons, or other basic particles of matter. 0 x 10-7 C but opposite signs are held 15 cm apart. the nonvanishing field components in the case of opposite and equal charges. Gravitational fields exert a force on objects of mass, and electric fields exert a force on objects of charge. The Electric Field. 1 Electric Charge There are two types of observed electric charge, which we designate as positive and negative. Since the field lines are parallel and the electric field is uniform between two parallel plates, a test charge would experience the same force of attraction or repulsion no matter where it is located in the field. •The direction will be different. is a vector and charge Q is a scalar, the electric field which is /Q is also a vector quantity, its direction being the direction of the force on charge Q, i. An electric charge is described by the electric field associated with it. The contribution from the other charge reduces the field a bit, but there is still a net field to the left in each case. Thats fine and dandy when considering two seperate charges but when considering a net effects of a dipole you should consider the system. Same direction: Add the magnitudes together to find the net field. It follows that the origin lies halfway between the two charges. On the left, vectors are drawn at various points to show the direction and magnitude of the electric field. The figure shows the electric field lines near two charges 1 and 2. Electric Charges Electric charge is a basic property of matter Two basic charges Positive and Negative Each having an absolute value of 1. • Electric fields around a point charge (a charged particle) • Electric fields between two point charges • Electric fields between two parallel metal charged plates - this is called a uniform an electric field In HSC Physics, almost always we have to work with questions that involve uniform electric fields. D) Somewhere between the two charges, but nearer to the −2q charge. Except near the edges, the excess charges distribute themselves uniformly, producing field lines that are uniformly spaced (hence uniform in strength) and perpendicular to the surfaces (hence. 0 μC and -8. This problem is a review of the relationship between an electric field , its associated electric potential , the electric potential energy , and the direction of force on a test charge. The above equation is a mathematical notation of for two charges. The first, the Mass Analyzer (MA), consisted of a velocity filter of crossed E and B fields (a Wien filter) in tandem with a curved-plate electrostatic energy-per-unit-charge filter and a channel electron multiplier behind both filters. where F is the force, q1 and q2 are the charge of the two objects (usually the same when considering two electrons), and r is the radius/distance between the two charges. 21-6 The Electric Field Example 21-7: E at a point between two charges. 1 Which law to use Apply Coulomb's law: where is the distance between the two charges. (a) What is the electric flux through the disk? (b) What is the flux through the disk if it is turned so that its normal is perpendicular to E?. So, the vector of electric field , determines how strongly an electric charge is repulsed or attracted by the charge which has created the electric field. Then for our configuration, a cylinder with radius r = 15. The charge in the top drawing is a +2 µC charge and that in the bottom is -5 µC. 0 x 10-7 C but opposite signs are held 15 cm apart. The electric field lines are directed away from a positive charge and towards a negative charge so that at any point , the tangent to a field line gives the direction of electric field at that. The Parallel Plate Capacitor: The electric field distribution of two oppositely charged metal plates. where k is a proportionality constant. 0 m C, are separated by a distance of 0. They always start at positive charges (also known as a source) or at infinity. The electric field between. A metal sphere is neutral because it has an equal number of protons and electrons. Electric field is defined as having the same direction as force on a positive charge. In this lab we will determine the electric field by finding equipotential surfaces. If the lines cross each other at a given location, then there must be two distinctly different values of electric field with their own individual direction at that given location. 31×10 −9 C. Finally, electric charge comes in two types, which we choose to call positive charge and negative charge. A negatively charged particle accelerates from East to West in a uniform electric field. Electric charges exert a force on each other. Example 21-7: E at a point between two charges. That's why, for example, two electrons with the elementary charge e = 1. Which one of the following statements is correct? A€€€€€ No energy is transferred when the movement is parallel to the direction of the field. E Field from 2 ChargesE Field from 2 Charges • Calculate electric field at point A due to two unequal charges - Draw electric fields - Calculate E from +7μC charge - Calculate E from -3. At which point is the electric field zero for the two point charges shown? +x +4 q −2 q A) It is never 0. 2: Electrostatic force between three non-colinear point charges Next: Example 3. Electric field is represented with E and Newton per coulomb is the unit of it. charge density. 5 cm from the -11 μ C is E1 = [1/4πεo] -11 μ / 0. Two particles having charges of 0. When an electron (q = -e) is in an electric field, the electron experiences a force in the direction opposite of the electric. (Hint: See Example 24. If we take the basic learning, which I mentioned, in accounts, it's very easy to understand that this is the direction of a positive charge object if we put the object between the plate (move away the positive charged plate and toward negatively charged plate). (II) The electric field midway between two equal but opposite point charges is and the distance between the charges is 16. good electrical insulators Coulomb's law for the force exerted by one charged particle on another • the electric field concept; representation of an. This direction is represented by an arrow. Possible student directions; Charge Moving Through Magnetic Field Basic: This lab was designed to have students figure out the formula for the force on a charge moving through a magnetic field. Electric field line simulator. The electric field is a vector quantity, and the direction of the field lines depends on the sign of the source charge. A third point charge of 3. Two particles having charges of 0. Field lines begin on positive charge and terminate on negative charge. Write your results on or near the points. The direction of an electric field at any point is the same as the direction of the force exerted on the positive test charge. Electric field vectors point away from positively charged sources, and toward negatively charged sources. The electric field lines between two oppositely charged objects curve in space. (C) results in an repulsive force between the electrons and the positively charged protons in an atom's nucleus. And it is directed normally away from the sheet of positive charge. Update: 3) A point charge q1=-4. The following setup will produce a 2D electric ﬁeld between two “point charges”. Thus, the magnitude of the electric field at point P is E = F/q 0, and the direction of is that of the force that acts on the positive test charge. Common SI units of electricity include the ampere (A) for current, coulomb (C) for electric charge, volt (V) for potential difference, ohm (Ω) for resistance, and watt (W) for power. Apparatus: Conducting Paper, mounting board, 1. If you throw a charge into a uniform electric field (same magnitude and direction everywhere), it would also follow a parabolic path. A positive charge has a force in the same direction as the electric field. Let's take parallel plates, which make a uniform electric field. The charge in the top drawing is a +2 µC charge and that in the bottom is -5 µC. Distance between two charges at points A and B, d = 15 + 15 = 30 cm = 0. = 1/4πεo] μ [15 -11]/ 0. An electron enters the capacitor from the left with a speed of 3>< 106 m/sec; its direction of motion is at right angles to both the magnetic field and the electric field as shown. 20 (each has a magnitude F = qE) Thus, the net force on the dipole is zero. Electric field near a negative charge is directed radially into the charge as shown Electric field near a positive charge is directed radially out from the charge - Electric Field Electric field lines show • direction of the force • indicate its relative magnitude Similar to gravitational field lines 2+ Electric field lines Double the charge. What is the magnitude and direction of the electric field at point A, 0. The direction of the electric field is the direction in which a positive charge placed at that position will move. What are the magnitude and direction of the Electric Field E at the point midway between the charges?. shows how the electric field from two point charges can be drawn by finding the total field at representative points and drawing electric field lines consistent with those points. In an electric field the charges move in the direction of. During this process, positive charges are drawn, while negative charges are repelled. Consider two lines intersect at a point then in such case two tangents can be drawn at that point which indicates two directions of the electric field Now if a unit charge is placed at that point then force acting on the unit charge due to field, is in two direction accordingly which is not possible. Electric Field Line Patterns Two equal but like point charges At a great distance from the charges, the field would be approximately that of a single charge of 2q The bulging out of the field lines between the charges indicates the repulsion between the charges The low field lines between the charges indicates a weak field in this region. SOLUTION: Directly between the two charges, the electric fields produced by each charge are equal in magnitude and point in opposite directions, so the two vectors add up to zero. This direction is represented by an arrow. Also magnetic fields of the Earth protects us fromte charged particles in cosmic rays as they are deflected by the magnetic field and many are prevented from hitting the atmosphere directly. Find the magnitude and direction of the electric field due to this particle at a point 0. What is the magnitude and direction of the electric field at point A, 0. The magnitude of the electric field E produced by a charged particle at a point P is the electric force per unit positive charge it exerts on another charged particle located at that point. One very important example of electric fields which is used extensively is the electric field between two charged parallel plates. The direction of the electric field at a point is given by the direction in which the potential decreases most rapidly. ('Test charge' means that the charge is brought to that location without disturbing the other charges. Electric fields (e-fields) are an important tool in understanding how electricity begins and continues to flow. Drawings using lines to represent electric fields around charged objects are very useful in visualizing field strength and direction. (a) Determine the direction and magnitude of the electric field at a point P between the two charges that is 2. The direction of the electric field at any given point is defined as the direction of the force that the field exerts on a positive test charge at that point. INTERPRET The electron and proton each carry one unit of electric charge, but the sign of the charge is opposite for the two particles. If the lines cross each other at a given location, then there must be two distinctly different values of electric field with their own individual direction at that given location. If you have larger charges, the forces will be larger. 5 cm from the 15 μ C is E1 = [1/4πεo] 15 μ / 0. (1 point) The number of electric field lines passing through a unit cross sectional area is indicative of: a. As shown in Fig. 85x10^4N/C) between two parallel charged plates. Electric field vectors point away from positively charged sources, and toward negatively charged sources. Dipole Charge: One positive and one negative charge. µC point charge. Electric field line simulator. Moreover, every single charge generates its own electric field. Remember that whenever work gets done, energy changes form. Which arrow best represents the direction of their resultant electric field at point P? 11. When drawing field lines that represent the forces due to a charged object, the arrows show the direction of the force on a positive charge. Electric Fields and WORK In order to bring two like charges near each other work must be done. The two charges q 1 and q 2 shown in the figure (Figure 1) have equal magnitudes. The field force is the amount of "push" that a field exerts over a certain distance. Let's first try to use Coulomb's Law to calculate the magnitude and direction of the electric force on a point charge when there are only two point charges present. The case of a constant Electric Field, as between charged parallel plate conductors, is a good example of the relationship between work and voltage. It is convenient for many applications to introduce the concept of the electric field , conventionally denoted by.
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