Physics 2 Chapter 22 Review questions
At a distance of one centimeter from an electron, the electric field strength has a value E. At what distance is the electric field strength equal to E/2?
1.4cm use the equation E1=E/2+r2^2
A positively charged object is located to the left of a negatively charged object as shown. Electric field lines are shown connecting the two objects. The five points on the electric field lines are labeled A, B, C, D, and E. At which one of these points would a test charge experience the smallest force?
A
Consider the electric field lines shown in the drawing. Which of the following statements correctly describes this situation?
A and B are both negatively charged particles.
Consider what would happen if electric field lines could cross each other. What would it mean if two electric field lines were to cross?
A test charge placed at the intersection of two electric field lines would experience a net force in two different directions at once.
Which of the following statements concerning electric field lines is false? a) Electric field lines between two charged particles are often curved. b) Electric field lines are a method proposed by Michael Faraday to map the electric field at various locations. c) Electric field lines can be used to indicate the local magnitude of the electric field. d) Electric field lines are always directed radially away from a positively charged particle. e) An electric field line indicates the direction of the force on an electron placed on the line.
An electric field line indicates the direction of the force on an electron placed on the line.
A positively charged object is located to the left of a negatively charged object as shown. Electric field lines are shown connecting the two objects. The five points on the electric field lines are labeled A, B, C, D, and E. At which one of these points would a test charge experience the largest force?
B
A positively charged object is located to the left of a negatively charged object as shown. Electric field lines are shown connecting the two objects. The five points on the electric field lines are labeled A, B, C, D, and E. At which one of these points would a test charge experience the smallest force?
B
Consider the following observations: (1) electric field lines are drawn connecting two point charges labeled A and B, (2) charge A is due north of charge B, and (3) a proton placed at the mid-point on a line connecting the two point charges travels due south. Which one of the following statements correctly indicates the signs of the two charges?
Charge A is positive and charge B is negative.
A positively charged object is located to the left of a negatively charged object as shown. Electric field lines are shown connecting the two objects. The five points on the electric field lines are labeled A, B, C, D, and E. At which one of these points would a test charge experience the largest force?
D
Consider the drawing which shows a uniform ring of charge of radius R. Which of the following expressions gives the correct dependence of the electric field at point P located on the z axis, where z >> R?
E is proportional to 1/z^2
Which one of the following expressions gives the correct relationship between the electric field strength E and the distance r from an electric dipole?
E is proportional to r
Which of the following expressions gives the electric field due to an infinite sheet of charge with a uniform charge density?
E=2chargedensity/Eor^3
A uniformly charged rod with a linear charge density l is located along the y axis as shown. The rod extends to infinity in both directions. Which of the following expressions gives the magnitude of the electric field at a point P located a distance d from the rod on the x axis?
E=lamnda/4piE0x
Two parallel infinite sheets of charge carry equal charge distributions s of opposite sign. Which of the following expressions gives the electric field in the region between the infinite sheets?
E=o-thing/E0
Which of the following combination of units are those for the strength of the electric field?
N/C
Which one of the following statements concerning the electric field is false? Which one of the following statements concerning the electric field is false? a) The SI unit of the electric field is the newton per meter (N/m) b) The electric field is a vector quantity. c) At a given point, a charged particle will experience a force, if an electric field is present at that location. d) If a positively-charged particle is placed at a location where the electric field is directed due north, it will be accelerated due north. e) The magnitude of the electric field at a particular location due to a particular charged particle is inversely proportional to the distance of the particle from that location.
The SI unit of the electric field is the newton per meter (N/m)
Which one of the following statements concerning the electric dipole moment is false? a) The dipole moment is a scalar quantity. b) The dipole moment has units of C×m. c) The dipole moment combines two intrinsic properties of an electric dipole, the distance between the charges and the amount of charge on each object. d) The dipole moment is directed from the negative charge toward the positive charge of the dipole. e) The direction of the dipole moment is used to specify the orientation of the dipole.
The dipole moment is a scalar quantity.
Which one of the following statements best describes the concept of the electric field?
The electric field is a distribution of vectors at points due to the presence of one or more charged objects creating a scalar potential field.
Consider the electric field lines shown in the drawing. Which of the following statements correctly describes this situation?
The electric field is due to particles that are both charged either positively or negatively.
Consider the following hypothetical situation: An infinitely long line of charge is located along the central axis of an infinitely long hollow cylinder of charge. Which of the following statements concerning the force on the line of charge is true? a) The force on the line of charge is infinite. b) The force on the line of charge is zero newtons. c) The force depends on the radius of the cylinder. It will be larger if the cylinder radius is large. d) The force depends on the radius of the cylinder. It will be smaller if the cylinder radius is large.
The force on the line of charge is zero newtons.
Two negatively-charged objects are located on the x axis, equally distant from the origin as shown. Consider the electric field at the point P1. How will that electric field change if a third object with a charge +q is placed at point P2? Note: the point P2 is the same distance from the origin as the point P1 and the magnitude of each of the charges is the same.
The magnitude of the electric field will decrease by 25%.
A positively-charged object is released from rest in a region containing a uniform electric field. Which one of the following statements concerning the subsequent motion of the object is correct?
The object will experience a constant acceleration and move in the direction of the electric field.
Two positively charged particles are in fixed locations on the x axis. A test charge that is free to move about the x-y plane is placed at the mid-point between the two positively charged particles. If the test charge is held stationary at the mid-point and then released, it remains stationary. Which of the following is the best explanation for this behavior?
The test charge is at a point of stable equilibrium for the x direction, but not for the y direction.
Why does the electric field due to a dipole decrease more rapidly with increasing distance than that for a single charge?
The total charge of the dipole is neutral (zero).
Four charges are located on the corners of a square as shown in the drawing. What is the direction of the net electric field at the point labeled P?
There is no direction. The electric field at P is zero N/C.
Complete the following statement: Electric field lines depend on
a) the direction of the electric field. b) the strength of the electric field. c) the force exerted on a test charge.
Which one of the following statements concerning charge distributions is false? a) Charge distributions consist of a very large number of closely spaced charges. b) Charge distributions may be uniform arrangements of charges along a line, over a surface, or throughout a volume. c) Calculus provides important tools for determining electric fields due to charge distributions. d) Charge distributions are treated as though composed of discrete charges. e) In dealing with charge distributions, it is often more useful to speak in terms of a charge density rather than the total charge
d) Charge distributions are treated as though composed of discrete charges.
Consider the drawing, where the solid lines with arrows represent the electric field due to the charged object. An electron is placed at the point P and released from rest. Which of the following vectors represents the direction of the force, if any, on the electron?
downward towards the left
The direction of the electric field is the same as which of the following properties related to a test charge?
force on a positive test charge
A single, positive test charge is brought near a dipole. Under what circumstances will the force exerted on the test charge by the
the test charge is very far from the dipole compared to the distance between the dipole charges
The drawing shows a hollow conducting sphere with a net positive charge uniformly distributed over its surface. A small negativelycharged object has been brought near the sphere as shown. What is the direction of the electric field at the center of the sphere?
to the right
Four charges are located on the corners of a square as shown in the drawing. What is the direction of the net electric field at the point labeled P?
toward the middle of the bottom side of the square
An electron traveling horizontally to the right enters a region where a uniform electric field is directed downward. What is the direction of the force exerted on the electron once it has entered the field?
upward
