Test 1

d. Both objects will attract each other.

A charged conductor is brought near an uncharged insulator. Which one of the following statements is true? Select one: a. Both objects will repel each other. b. The objects will attract each other only if the conductor has a positive charge. c. The objects will repel each other only if the conductor has a negative charge. d. Both objects will attract each other. e. Neither object exerts an electrical force on the other.

e. downward

An electron traveling horizontally enters a region where a uniform electric field is directed upward. What is the direction of the force exerted on the electron once it has entered the field? a. to the right b. out of the page, toward the reader c. upward d. to the left e. downward

d. The electric potential of A equals that of B.

An isolated system consists of two conducting spheres A and B. Sphere A has five times the radius of sphere B. Initially, the spheres are given equal amounts of positive charge and are isolated from each other. The two spheres are then connected by a conducting wire.Note: The potential of a sphere of radius R that carries a charge Q is V = kQ/R, if the potential at infinity is zero. Which one of the following statements is true after the spheres are connected by the wire? Select one: a. The electric potential of A is 25 times larger than that of B. b. The electric potential of A is five times larger than that of B. c. The electric potential of A is 1/5 as large as that of B. d. The electric potential of A equals that of B. e. The electric potential of A is 1/25 as large as that of B.

b. The electric field is zero somewhere on the x axis to the right of the 2q charge.

At which point (or points) is the electric field zero N/C for the two point charges shown on the x axis? (you don't need to calculate the electric field)Screen Shot 2019-09-29 at 4.29.29 PM a. The electric field is zero at two points along the x axis; one such point is to the right of the 2q charge and the other is to the left of the +4q charge. b. The electric field is zero somewhere on the x axis to the right of the 2q charge. c. The electric field is never zero in the vicinity of these charges. d. The electric field is zero somewhere on the x axis between the two charges, but this point is nearer to the 2q charge. e. The electric field is zero somewhere on the x axis to the left of the +4q charge.

c. the total current through the battery will increase

Complete the following statement: A simple series circuit contains a resistance R and an ideal battery. If a second resistor is connected in parallel with R, Select one: a. the equivalent resistance of the circuit will increase. b. the current through R will decrease. c. the total current through the battery will increase. d. the rate of energy dissipation in R will increase. e. the voltage across R will decrease.

d. the sign of the charge causing the field.

Complete the following statement: The magnitude of the electric field at a point in space does not depend upon Select one: a. the magnitude of the charge causing the field. b. the force that a unit positive charge will experience at that point. c. the force that a unit negative charge will experience at that point. d. the sign of the charge causing the field. e. the distance from the charge causing the field.

c. negative charges are transferred from the fur to the rod.

Complete the following statement: When an ebonite rod is rubbed with animal fur, the rod becomes negatively charged as Select one: a. negative charges are created on the surface of the rod. b. negative charges are transferred from the rod to the fur. c. negative charges are transferred from the fur to the rod. d. positive charges are transferred from the rod to the fur. e. positive charges are transferred from the fur to the rod.

...b. A is positive B is negative C is positive D is neutral E is neutral

Five styrofoam balls are suspended from insulating threads. Several experiments are performed on the balls; and the following observations are made: I. Ball A attracts B and A repels C. II. Ball D attracts B and D has no effect on E. III. A negatively charged rod attracts both A and E.What are the charges, if any, on each ball? a. A is negative B is positive C is negative D is neutral E is neutral b. A is positive B is negative C is positive D is neutral E is neutral c. A is positive B is negative C is positive D is neutral E is positive d. A is positive B is neutral C is negative D is positive E is neutral e. A is positive B is negative C is positive D is positive E is neutral

b. B

Four point charges, each of the same magnitude, with varying signs are arranged at the corners of a square as shown. Which of the arrows labeled A, B, C, and D gives the correct direction of the net force that acts on the charge at the upper right corner? Screen Shot 2019-09-29 at 4.28.33 PM a. D b. B c. A d. C e. the net force on the charge is zero.

d. The electric field will be zero, but the electric potential remains unchanged.

Suppose that the charges are rearranged as shown in this figure. Which one of the following statements is true for this new arrangement? a. Both the electric field and the electric potential are zero at P. b. Both the electric field and the electric potential will be changed and will be non-zero. c. The electric field will remain unchanged, but the electric potential will decrease. d. The electric field will be zero, but the electric potential remains unchanged. e. The electric field will remain unchanged, but the electric potential will be zero.

b. increase by a factor of four.

The current through a certain heater wire is found to be fairly independent of its temperature. If the current through the heater wire is doubled, the amount of energy delivered by the heater in a given time interval will Select one: a. decrease by a factor of four. b. increase by a factor of four. c. decrease by a factor of two. d. increase by a factor of eight. e. increase by a factor of two.

d. The magnitude of the ratio (q2/ q1) is less than one.

The figure shows the electric field lines in the vicinity of two point charges. Which one of the following statements concerning this situation is true? a. Both q1and q2 have the same sign of charge. b. The electric field is strongest midway between the charges. c. The magnitude of the electric field is the same everywhere. d. The magnitude of the ratio (q2/ q1) is less than one. e. q1 is negative and q2 is positive.

c. The resistance is not changed.

The potential difference across the ends of a wire is doubled in magnitude. If Ohm's law is obeyed, which one of the following statements concerning the resistance of the wire is true? Select one: a. The resistance is one half of its original value. b. The resistance increases by a factor of four. c. The resistance is not changed. d. The resistance decreases by a factor of four. e. The resistance is twice its original value.

e. I

The sketch below shows cross sections of equipotential surfaces between two charged conductors that are shown in solid grey. Various points on the equipotential surfaces near the conductors are labeled A, B, C, ..., I. At which of the labeled points will the electric field have the greatest magnitude? a. G b. D c. A d. H e. I

e. The magnitude and direction of the force are dependent on all of the above choices.

Two charged particles A and B are located near one another. Both the magnitude and direction of the force that particle A exerts on particle B is independent of Select one: a. the sign of charge B. b. the distance between A and B. c. the sign of charge A. d. the magnitude of the charge on B. e. The magnitude and direction of the force are dependent on all of the above choices.

c. The direction makes a 135° angle below the horizontal direction.

Two positive charges are located at points A and B as shown in the figure. The distance from each charge to the point P is a = 2.0 m. Which statement is true concerning the direction of the electric field at P? a. The direction is toward A. b. The direction is directly away from A. c. The direction makes a 135° angle below the horizontal direction. d. The direction makes a 45° angle above the horizontal direction. e. The direction is toward B. Screen Shot 2019-09-29 at 4.34.24 PM

d. Sphere A is negative Sphere B is positive

Two uncharged, conducting spheres, A and B, are held at rest on insulating stands and are in contact. A positively charged rod is brought near sphere A as suggested in the figure. While the rod is in place, someone moves sphere B away from A. How will the spheres be charged, if at all? Screen Shot 2019-09-29 at 4.27.19 PM a. Sphere A is positive Sphere B is negative b. Sphere A is negative Sphere B is negative c. Sphere A is neutral Sphere B is neutral d. Sphere A is negative Sphere B is positive e. Sphere A is positive Sphere B is positive

c. The current is half as much as that in B.

Two wires A and B are made of the same material and have the same diameter. Wire A is twice as long as wire B. If each wire has the same potential difference across its ends, which one of the following statements is true concerning the current in wire A? Select one: a. The current is one-fourth that in B. b. It is twice as much as that in B. c. The current is half as much as that in B. d. The current is four times that in B. e. The current is equal to the current in B.

a) The potential drop across each resistor will be the same.

Which of these statements is true about resistors connected in parallel? a) The potential drop across each resistor will be the same. b) Both the current passing through and the potential drop across each resistor are different. c)The same amount of current will pass through each resistor. d) Both the current passing through and the potential drop across each resistor are the same.

b) The same amount of current will pass through each resistor.

Which of these statements is true about resistors connected in series? a) Both the current passing through and the potential drop across each resistor are the same. b) The same amount of current will pass through each resistor. c) The potential drop across each resistor will be the same. d)Both the current passing through and the potential drop across each resistor are different.

b. e

Which one of the following circuits has the largest resistance? a. c b. e c. a d. b e. d

a. a beam of electrons moves southward

Which one of the following situations results in a conventional electric current that flows northward? Select one: a. a beam of electrons moves southward b. a beam of protons moves eastward c. an electric dipole moves southward d. a beam of protons moves northward e. a beam of electrons moves northward

d. The paper becomes electrically polarized by induction.

Which one of the following statements best explains why tiny bits of paper are attracted to a charged rubber rod? Select one: a. Paper is naturally a negative material. b. The paper acquires a net positive charge by induction. c. Rubber and paper always attract each other. d. The paper becomes electrically polarized by induction. e. Paper is naturally a positive material.

b. No force component acts along the path of a charge as it is moved along an equipotential surface.

Which one of the following statements concerning electrostatic situations is false? Select one: a. Equipotential surfaces are always perpendicular to E. b. No force component acts along the path of a charge as it is moved along an equipotential surface. c. If V is constant throughout a region of space, then E must be zero in that region. d. Zero work is needed to move a charge along an equipotential surface. e. E is zero everywhere inside a conductor.

e. The current through each resistor is the same

Which one of the following statements concerning resistors in series is true? Select one: a. The rate at which charge flows through each resistor depends on its resistance. b. The power dissipated by each resistor is the same. c. The voltage across each resistor is the same. d. The total current through the resistors is the sum of the current through each resistor. e. The current through each resistor is the same.

e. It is a measure of the electric force per unit charge on a test charge.

Which one of the following statements is true concerning the magnitude of the electric field at a point in space? Select one: a. It is a measure of the electric force per unit mass on a test charge. b. It is a measure of the ratio of the charge on an object to its mass. c. It is a measure of the total charge on the object. d. It is a measure of the electric force on any charged object. e. It is a measure of the electric force per unit charge on a test charge.