Electric Field and Potential Questions and Answers

Two particles with equal charge experience a force of 10 nN when they are 30 cm apart. What is the magnitude of the charge on each particle? A. -5.8 × 10^-10 C B. -3.2 × 10^-10 C C. +3.2 × 10^-10 C x D. +1.4 x 10^-5 C

How is the charge of the proton related to the charge of the electron? A. The magnitudes of charge of the proton and the electron are equal, but the charge of the proton is positive, whereas the charge of the electron is negative. B. The magnitudes of charge of the proton and the electron are unequal, but the charge of the proton is positive, whereas the charge of the electron is negative. C. The magnitudes of charge of the proton and the electron are equal, but the charge of the proton is negative, whereas the charge of the electron is positive. D. The magnitudes of charge of the proton and the electron are unequal, but the charge of the proton is negative, whereas the charge of the electron is positive.

When a negative charge is released from rest and moves along an electric field line, it moves to a position of: a) lower potential and lower potential energy b) lower potential and higher potential energy c) higher potential and lower potential energy d) higher potential and higher potential energy e) decreasing magnitude of the electric field

8. Two conducting spheres, sphere A with radius R and charge Q, and sphere B with radius 3R and charge 7/3 Q, are separated. By connecting these two spheres by a thin copper wire, how much charge will transfer to sphere A? a) (-1/6) Q b) (5/6) Q c) (-2/3) Q d) (1/6) Q e) (5/2) Q

A charged wooden stick is balanced on a pivot so it can rotate freely. If an uncharged metal rod is brought close to the charged end of the stick, the rod will a) exert no electrostatic force on the stick b) always oscillate about the pivot point c) be repelled by the stick d) be either attracted or repelled, depending on the sign of charge on the stick e) be attracted by the stick

There are very large numbers of charged particles in most objects. Why, then, don't most objects exhibit static electric effects? A. Most objects are neutral. B. Most objects have positive charge only. C. Most objects have negative charge only. D. Most objects have excess protons.

Four charges, each with charge, q, are placed at the corners of a rhombus. A fifth charge, with charge -4q, is placed at the center of the rhombus. Determine the energy stored in the system

Suppose you are near an electrical box than warns about high voltage. It mentions voltages of up to 2000 V can be found inside the box. The box is shielded in metal. a. If an object is at a potential of 2000 V, how close can you get to it (in our atmosphere) without getting shocked? Use google to find the electrical breakdown value for air. (Specifically, this is an electric field). b. What are some reasons that you don't get shocked when you lean up on the outside of the box?

The figure shows a uniformly charged thin rod of length Z that has a total charge Q. The charge is uniformly distributed along the rod. Determine an expression for the magnitude of the electrostatic force acting on an electron positioned on the axis of the rod at a distance d from the midpoint of the rod.

A small metal ball with a mass of 4.0 g and a charge of 5.0 mC is located a distance of 0.70 m above the ground in an electric field of 12.0 N/C directed to the east. The ball is then released from rest. What is the velocity of the ball after it has moved downward a vertical distance of 0.30 m? (4.41 m/s, 32º below the horizontal}

An electron has an initial speed of 6.83 x 10^6 m/s in a uniform 5.98 x 10^5 N/C strength electric field. The field accelerates the electron in the direction opposite to its initial velocity. (a) What is the direction of the electric field? opposite direction to the electron's initial velocity same direction as the electron's initial velocity not enough information to decide (b) How far does the electron travel before coming to rest? (c) How long does it take the electron to come to rest? (d) What is the electron's speed when it returns to its starting point?

2) Can we produce an electric field in which the electric field lines are parallel and equally spaced? If so, please describe how this can be done. (1 point)

What is the electric field produced at a point P above the center of a solid cylinder with volume charge density of p? Point P is located along the z axis and is h distance away from the top of the cylinder. The cylinder has radius R and height H. Hint: You can start with the disc from lecture 2.4 and integrate along z.

19. Three identical particles, each possessing the mass m and charge + q. are placed at the corners of an equilateral triangle with side ro. The particles are simultaneously set free and start flying apart symmetrically due to Coulomb's repulsion forces. The work performed by Coulomb's forces acting on each particle until the particles fly from one another to a very large distance is (where k =1/4πE0.) (A) 3kq^2/r0 (B) kq²/r0 (C) 3kq²/2r0 (D) kq²/2r0

11. The metal knob of a gold leaf electroscope is touched with a positively charged rod. When it is taken away the leaves stay separated. Now the metal knob is touched by negatively charged rod. The separation between the leaves (A) increases (B) decreases (C) remains same (D) first increases then decreases.

If two charges move four times further apart, their electrostatic force changes by a factor of: Select one: a. 1/4 b. 16 c. 1/16 d. 4

What is the potential difference between two plates that are located 0.55 m apart? Assume the magnitude of the electric field between the two plates is 5.39 x 10^6 N/C. Select one: a. 2.96 x 10^6 V b. 7.83 x 10^9 V c. -5.66 x 10^4 V d. -2.96 x 10^6 V

On the x-axis, a charge -2Q and a charge +Q are fixed at the origin and x-1 meter position respectively. If a test charge +q is also placed in the x-axis, find the coordinate for +q so that the total Coulomb force due to both -2Q and +Q is zero. Enter only numerical results without the unit meter

21.11. Two very small 8.55-g spheres, 15.0 cm apart from cen- ter to center, are charged by adding equal numbers of electrons to each of them. Disregarding all other forces, how many electrons would you have to add to each sphere so that the two spheres will accelerate at 25.0g when released? Which way will they accelerate?

Two flat, parallel electrodes 2.5 cm apart are kept at potentials of 30 V and 45 V. Estimate the electric field strength between them.

In a certain region of space, the electric potential is V (x, y, z) = Axy-Ba²+ Cy, where A, B, and C are positive constants. For related problem-solving tips and strategies, you may want to view a Video Tutor Solution of Potential and field of a point charge. Calculate the x-component of the electric field. Express your answer in terms of some or all of the variables A, B, C, x, and y. Calculate the y-component of the electric field. Express your answer in terms of some or all of the variables A, B, C, x, and y.

A parallel-plate air capacitor with a capacitance of 253 pF has a charge of magnitude 0.138 μC on each plate. The plates have a separation of 0.316 mm. What is the potential difference between the plates? What is the area of each plate? What is the electric field magnitude between the plates?

Two identical air-filled parallel-plate capacitors C₁ and C2 are connected in series to a battery that has voltage V. The charge on each capacitor is Qo. While the two capacitors remain connected to the battery, a dielectric with dielectric constant K> 1 is inserted between the plates of capacitor C₁, completely filling the space between them. What is the charge on capacitor C₁ after the dielectric is inserted? Express your answer in terms of K and Qo.

Show all work; FBD where appropriate. May have to look up constants such as masses of subatomic particles 4. Three identical point charges of 2.0 µC are placed on the x-axis. The first charge is at the origin, the second to the right at x = 50 cm, and the third is at the 100 cm mark. a. sketch a FBD of the charge at the origin. b. What are the magnitude and direction of the electrostatic force which acts on the charge at the origin?

A uniform magnetic field is present in a cylindrical region. It starts changing at a constant rate. A conducting wire loop is placed symmetrically as shown. A. Electric field in the loop wire will be conservative B. Electric field in the loop wire will be non-conservative only C. There will be no electric field in loop wire. D. Electric field in the loop wire will be conservative as well as non-conservative

In a certain region of the space the electric field at a point whose position vector is 7 is given by E(r)=, where a = 180 Nm/C. How much electric charge in nC is enclosed inside a sphere of radius R = 0.5 m centered at origin?

A flexible spherical shell of radius R with uniformly distributed charge q is expanded to a radius 2R. The work performed by the electric force in this process is equal to. The value of Nis

Two idendical metallic balls of radius a are placed in a homogeneous poorly conducting medium with resistivity p. If the distance between balls is much larger than their size and balls are given +q and -q charges, then (A) Resistance of medium between the balls is 2na (B) Resistance of medium between the balls is 4xa (C) Potential difference across the balls decreases exponentially (D) Potential difference across the balls decreases linearly

A point charge of -3.00 μC is located in the center of a spherical cavity of radius 6.50 cm inside an insulating spherical charged solid. The charge density in the solid is 7.35 x 10-4 C/m³. Calculate the magnitude of the electric field inside the solid at a distance of 9.40 cm from the center of the cavity. Find the direction of this electric field.

Four identical metal spheres initially have the following charges on them: QA = -6 µC, QB = +3 µC, Qc = -4 μC, and QD = +7 μC. Spheres A and C are brought into contact which each other. After a short time, the spheres are separated again. Spheres B and D are brought into contact which each other. After a short time, the spheres are separated again. Finally Spheres A and B are brought into contact which each other. After a short time, the spheres are separated again. What is the final charge on each sphere? Select one: a. QA = -5 μC, QB = +5 μC, Qc = 0 μC, and Qp = 0 μC b. QA = 0 μC, QB = 0 μC, Qc = -5 µC, and Qp = +5 µC c. QA = 0 μC, QB = 0 μC, Qc = 0 μC, and Qp = 0 μC d. QA = -5 μC, QB = +5 μC, Qc = -5 μC, and Qp = +5 µC

Two very long uniform lines of charge are parallel and are separated by 0.480 m. Each line of charge has charge per unit length +4.80 μC/m. What magnitude of force does one line of charge exert on a 0.0550 m section of the other line of charge? Express your answer with the appropriate units.

(a) Find the electric potential difference VB - VA due to a point charge 91 = -2.92 nC that is 0.200 m from location A and 0.470 m from location B. (b) A charge q2 moving from B to A gains in kinetic energy. What is the sign of this charge? negative positive

Two concentric conducting spheres are uncharged, and in the space between them, at a distance L from the centre, a point charge Q is fixed. The radius of the inner sphere is r and the radius of the outer sphere is R. Now both spheres are connected by a thin conductor. A. The potential difference between spheres in the initial state is kQ(1/L-1/R). B. The final common potential of both the spheres is kQ(1/r-1/L) C. The potential difference between the spheres in the initial state is kQ/R D. A charge of Q ((1/L-1/R)/(1/r-1/R)) will flow through the conductor

Consider a dipole made up of charges 2.5 µC and -2.5 µC kept at (0.125 mm, 0, 0) and (-0.125mm, 0, 0) respectively. Find the magnitude of the electric field (in mN/C) due to this dipole at (2√2m, √17m, 0).

A 25 nC charge is moved from a point where V = 170 V to a point where V=-110 V. How much work is done by the force that moves the charge?

A +1.70 μC point charge is sitting at the origin. What is the radial distance between the 500 V equipotential surface and the 1000 V surface? Express your answer with the appropriate units.

A charge of -2.65 nC is placed at the origin of an zy-coordinate system, and a charge of 1.65 nC is placed on the y axis at y = 3.60 cm. If a third charge, of 5.00 nC, is now placed at the point x = 3.05 cm, y = 3.60 cm find the and y components of the total force exerted on this charge by the other two charges.

Consider a square surface of side 2a, a circular area is removed from the square symmetrically of radius a, A charge q is placed at distance a on the axis of circle. The flux through remaining part is q/6ε₀(3/√N - N). Find N.

Consider a charged parallel-plate capacitor. How can its capacitance be halved? Check all that apply. Double the charge. Double the plate area. Double the plate separation. Halve the charge. Halve the plate area. Halve the plate separation.

Calculate the induced dipole moment per unit volume (polarization density) of helium gas when it is placed in a field of 6 x 105 V/m. The atomic polarizability of helium is 0.18 x 100 Fm² and the concentration of helium atom is 2.6 x 1025/m³. Also calculate the separation of positive and negative charges in each atom.

An unknown charge is placed into an electric field 3.85 x 106 N/C East. This results in an electric force of 8.57 x 103 N West. What is the net charge of the object? Select one: a. +4.49 x 10² C b. -4.49 x 10² C c. +2.23 x 10-3 C d. -2.23 x 10-3 C

In Gauss's theorem ∫E.ds=q/ε The surface integral is evaluated by choosing a closed surface called the Gaussian surface. Here (A) The closed surface can be of any shape or size (B) q is the net charge enclosed inside the Gaussian surface, charges outside the surface are not considered (C) E is the electric field due to all charges on the surface (D) The exact location of the charges inside the surface does not affect the value of the integral

A small cork with an excess charge of +5.0 μC is placed 0.21 m from another cork, which carries a charge of -3.2 μC. What is the magnitude of the electric force between the corks? The Coulomb constant is 8.98755 × 10⁹ Nm²/C². Answer in units of N.

In the figure particles 2 and 4, of charge -e, are fixed in place on a y axis, at y₂ = -8.12 cm and y4 = 4.06 cm. Particles 1 and 3, of charge - e, can be moved along the x axis. Particle 5, of charge +e, is fixed at the origin. Initially particle 1 is at x₁ = -8.12 cm and particle 3 is at x3 = 8.12 cm. (a) To what x value must particle 1 be moved to rotate the direction of the net electric force net on particle 5 by 30 counterclockwise? (b) With particle 1 fixed at its new position, to what x value must you move particle 3 to rotate back to its original direction?

A point charge of +4.0 μC is held fixed at the origin. A second charge of -4.0 μC and mass 3.6 x 10^-2 kg is placed on the axis and released. Where should the charge be placed so that its initial acceleration will be +1.0 m/s²? (Neglect gravity.)

Three conducting spheres are electrically-charged. Sphere X is attracted to a negative Van De Graaff generator. Sphere Y is repelled by Sphere X. Sphere Z is attracted to Sphere Y. What is the charge of Sphere Z? Positive Negative Neutral Cannot be determined

4. a. If an electric field with magnitude 9,000 N/C is created 0.2 meters from a point charge, what is the magnitude of the charge? b. What magnitude of force would a proton experience at this location in the electric field?

What is the electric field strength at a point in space where a proton experiences an acceleration of 1.9 million "g's"? Express your answer using two significant figures.

A charged rod can induce a charge on both conducting and insulating materials. Which statement best describes Material A? Material A is a conductor; conducting materials tend to hold electrons in place Material A is an insulator; insulating materials tend to hold electrons in place Material A is a conductor; conducting materials generally allow electrons to move through the material Material A is an insulator; insulating materials generally allow electrons to move through the material

Uniform charge of 8.85 x 10-10 C/m² is distributed on surface of hollow cone of radius 10cm. Interaction potential energy of cone with a proton placed at vertex of cone is n x 10^-19. Find n.