Quiz 26: The Electric Field
Physics & Astronomy
Q 1Q 1
The figure shows two unequal point charges, q and Q, of opposite sign. Charge Q has greater magnitude than charge q. In which of the regions X, Y, Z will there be a point at which the net electric field due to these two charges is zero?
A) only regions X and Z
B) only region X
C) only region Y
D) only region Z
E) all three regions
Free
Multiple Choice
B
Q 2Q 2
Two point charges Q1 and Q2 of equal magnitudes and opposite signs are positioned as shown in the figure. Which of the arrows best represents the net electric field at point P due to these two charges?
A) A
B) B
C) C
D) D
E) The field is equal to zero at point P.
Free
Multiple Choice
A
Q 3Q 3
Four equal negative point charges are located at the corners of a square, their positions in the xy-plane being (1, 1), (-1, 1), (-1, -1), (1, -1). The electric field on the x-axis at (1, 0) points in the same direction as
A) .
B) .
C) -
D) .
E) - .
Free
Multiple Choice
C
Q 4Q 4
Three equal negative point charges are placed at three of the corners of a square of side d as shown in the figure. Which of the arrows represents the direction of the net electric field at the center of the square?
A) A
B) B
C) C
D) D
E) The field is equal to zero at point P.
Free
Multiple Choice
Q 5Q 5
The figure shows three electric charges labeled Q1, Q2, Q3, and some electric field lines in the region surrounding the charges. What are the signs of the three charges?
A) Q1 is positive, Q2 is negative, Q3 is positive.
B) Q1 is negative, Q2 is positive, Q3 is negative.
C) Q1 is positive, Q2 is positive, Q3 is negative.
D) All three charges are negative.
E) All three charges are positive.
Free
Multiple Choice
Q 6Q 6
Two large, flat, horizontally oriented plates are parallel to each other, a distance d apart. Half way between the two plates the electric field has magnitude E. If the separation of the plates is reduced to d/2 what is the magnitude of the electric field half way between the plates?
A) 4E
B) 2E
C) E
D) 0
E) E/2
Free
Multiple Choice
Q 7Q 7
Two very large parallel sheets a distance d apart have their centers directly opposite each other. The sheets carry equal but opposite uniform surface charge densities. A point charge that is placed near the middle of the sheets a distance d/2 from each of them feels an electrical force F due to the sheets. If this charge is now moved closer to one of the sheets so that it is a distance d/4 from that sheet, what force will feel?
A) 4F
B) 2F
C) F
D) F/2
E) F/4
Free
Multiple Choice
Q 8Q 8
An electron is initially moving to the right when it enters a uniform electric field directed upwards. Which trajectory shown below will the electron follow?
A) trajectory W
B) trajectory X
C) trajectory Y
D) trajectory Z
Free
Multiple Choice
Q 9Q 9
Two point charges of +20.0 μC and -8.00 μC are separated by a distance of 20.0 cm. What is the magnitude of electric field due to these charges at a point midway between them? (k = 1/4πε0 = 8.99 × 109 N ∙ m2/C2)
A) 25.2 × 106 N/C directed toward the negative charge
B) 25.2 × 106 N/C directed toward the positive charge
C) 25.2 × 105 N/C directed toward the negative charge
D) 25.2 × 105 N/C directed toward the positive charge
E) 25.2 × 104 N/C directed toward the negative charge
Free
Multiple Choice
Q 10Q 10
A point charge Q = -500 nC and two unknown point charges, q1 and q2, are placed as shown in the figure. The electric field at the origin O, due to charges Q, q1 and q2, is equal to zero. The charge q1 is closest to
A) 130 nC.
B) 76 nC.
C) 150 nC.
D) -76 nC.
E) -130 nC.
Free
Multiple Choice
Q 11Q 11
Two point charges, Q1 = -1.0 μC and Q2 = + 4.0 μC, are placed as shown in the figure.
(k = 1/4πε0 = 8.99 × 109 N ∙ m2/C2) The y component of the electric field, at the origin O, is closest to
A) 6.0 × 10-3 N/C.
B) -6.0 × 10-3 N/C.
C) 3.8 × 10-3 N/C.
D) -3.8 × 10-3 N/C.
E) 7.1 × 10-3 N/C.
Free
Multiple Choice
Q 12Q 12
Three +3.0-μC point charges are at the three corners of a square of side 0.50 m. The last corner is occupied by a -3.0-μC charge. Find the magnitude of the electric field at the center of the square.
(k = 1/4πε0 = 8.99 × 109 N ∙ m2/C2)
Free
Short Answer
Q 13Q 13
Three equal negative point charges are placed at three of the corners of a square of side d. What is the magnitude of the net electric field at the center of the square? (k = 1/4πε0 = 8.99 × 109 N ∙ m2/C2)
Free
Short Answer
Q 14Q 14
A 5.0-μC point charge is placed at the 0.00 cm mark of a meter stick and a -4.0-μC point charge is placed at the 50 cm mark. At what point on a line joining the two charges is the electric field due to these charges equal to zero?
Free
Short Answer
Q 15Q 15
A 3.0-μC positive point charge is located at the origin and a 2.0 μC positive point charge is located at x = 0.00 m, y = 1.0 m. Find the coordinates of the point where the net electric field strength due to these charges is zero.
A) x = 0.00 m, y = 0.55 m
B) x = 0.00 m, y = 0.67 m
C) x = 0.00 m, y = 1.5 m
D) x = 0.00 m, y = 0.60 m
Free
Multiple Choice
Q 16Q 16
Two thin 80.0-cm rods are oriented at right angles to each other. Each rod has one end at the origin of the coordinates, and one of them extends along the +x-axis while the other extends along the +y-axis. The rod along the +x-axis carries a charge of -15.0 µC distributed uniformly along its length, and the other rod carries +15.0 µC uniformly over its length. Find the magnitude and direction of the net electrical force that these two rods exert on an electron located at the point (40.0 cm, 40.0 cm).
(e = 1.60 × 10-19 C, ε0 = 8.85 × 10-12 C2/N ∙ m2)
Free
Essay
Q 17Q 17
A very long wire carries a uniform linear charge density of 7.0 nC/m. What is the electric field strength 16.0 m from the center of the wire at a point on the wire's perpendicular bisector?
(ε0 = 8.85 × 10-12 C2/N ∙ m2)
A) 7.9 N/C
B) 3.9 N/C
C) 0.49 N/C
D) 0.031 N/C
Free
Multiple Choice
Q 18Q 18
At a distance of 4.3 cm from the center of a very long uniformly charged wire, the electric field has magnitude 2000 N/C and is directed toward the wire. What is the charge on a 1.0 cm length of wire near the center? (ε0 = 8.85 × 10-12 C2/N ∙ m2)
A) -0.048 nC
B) -0.052 nC
C) -0.044 nC
D) -0.056 nC
Free
Multiple Choice
Q 19Q 19
A long, thin rod parallel to the y-axis is located at x = -1.0 cm and carries a uniform linear charge density of +1.0 nC/m. A second long, thin rod parallel to the z-axis is located at x = +1.0 cm and carries a uniform linear charge density of -1.0 nC/m. What is the net electric field due to these rods at the origin? (ε0 = 8.85 × 10-12 C2/N ∙ m2)
A) (-3.6 × 103 N/C)
B) (1.8 × 103 N/C)
C) (-1.8 × 103 N/C)
D) (3.6 × 103 N/C)
E) zero
Free
Multiple Choice
Q 20Q 20
A thin, circular disk of radius 30.0 cm is oriented in the yz-plane with its center at the origin. The disk carries a total charge of +3.00 μC distributed uniformly over its surface. Calculate the magnitude of the electric field due to the disk at the point x = 15.0 cm along the x-axis. (ε0 = 8.85 × 10-12 C2/N ∙ m2)
A) 9.95 × 105 N/C
B) 4.98 × 105 N/C
C) 3.31 × 105 N/C
D) 2.49 × 105 N/C
E) 1.99 × 105 N/C
Free
Multiple Choice
Q 21Q 21
In the figure, a ring 0.71 m in radius carries a charge of + 580 nC uniformly distributed over it. A point charge Q is placed at the center of the ring. The electric field is equal to zero at field point P, which is on the axis of the ring, and 0.73 m from its center. (ε0 = 8.85 × 10-12 C2/N ∙ m2) The point charge Q is closest to
A) -210
B) -300
C) -420
D) 210
E) 300
Free
Multiple Choice
Q 22Q 22
Two very large, flat plates are parallel to each other. Plate A, located at y = 1.0 cm, is along the xz-plane and carries a uniform surface charge density -1.00 μC/m2. Plate B is located at y = -1.0 cm and carries a uniform surface charge density +2.00 μC/m2. What is the electric field vector at the point having x, y, z coordinates (-0.50 cm, 0.00 cm, 0.00 cm)? (ε0 = 8.85 × 10-12 C2/N ∙ m2)
A) (+1.13 × 105 N/C)
B) (-2.83 × 105 N/C)
C) (+1.19 × 105 N/C)
D) (+1.69 × 105 N/C)
E) (-1.19 × 105 N/C)
Free
Multiple Choice
Q 23Q 23
An electric field is set up between two parallel plates, each of area 2.0 m2, by putting 1.0 μC of charge on one plate and -1.0 μC of charge on the other. The plates are separated by 4.0 mm with their centers opposite each other, and the charges are distributed uniformly over the surface of the plates. What is the magnitude of the electric field between the plates at a distance of 1.0 mm from the positive plate, but not near the edges of the plates? (ε0 = 8.85 × 10-12 C2/N ∙ m2)
A) 4.2 × 104 N/C
B) 1.4 × 104 N/C
C) 3.1 × 104 N/C
D) 0.00 N/C
E) 5.6 × 104 N/C
Free
Multiple Choice
Q 24Q 24
Two flat 4.0 cm × 4.0 cm electrodes carrying equal but opposite charges are spaced 2.0 mm apart with their midpoints opposite each other. Between the electrodes but not near their edges, the electric field strength is 2.5 × 106 N/C. What is the magnitude of the charge on each electrode? (ε0 = 8.85 × 10-12 C2/N ∙ m2)
A) 35 nC
B) 18 nC
C) 16 nC
D) 30 nC
Free
Multiple Choice
Q 25Q 25
The electric field strength in the space between two closely spaced parallel disks is 1.0 × 105 N/C. This field is the result of transferring 3.9 × 109 electrons from one disk to the other. What is the diameter of the disks? (e = 1.60 × 10-19 C, ε0 = 8.85 × 10-12 C2/N ∙ m2)
A) 3.0 cm
B) 1.5 cm
C) 4.5 cm
D) 6.0 cm
Free
Multiple Choice
Q 26Q 26
A pair of charged conducting plates produces a uniform field of 12,000 N/C, directed to the right, between the plates. The separation of the plates is 40 mm. An electron is projected from plate A, directly toward plate B, with an initial velocity of vo = 2.0 × 107 m/s, as shown in the figure. (e = 1.60 × 10-19 C, ε0 = 8.85 × 10-12 C2/N ∙ m2, mel = 9.11 × 10-31 kg) The velocity of the electron as it strikes plate B is closest to
A) 1.2 × 107 m/s.
B) 1.5 × 107 m/s.
C) 1.8 × 107 m/s.
D) 2.1 × 107 m/s.
E) 2.4 × 107 m/s.
Free
Multiple Choice
Q 27Q 27
A pair of charged conducting plates produces a uniform field of 12,000 N/C, directed to the right, between the plates. The separation of the plates is 40 mm. An electron is projected from plate A, directly toward plate B, with an initial velocity of v0 = 1.0 × 107 m/s, as shown in the figure. (e = 1.60 × 10-19 C, ε0 = 8.85 × 10-12 C2/N ∙ m2, mel = 9.11 × 10-31 kg) The distance of closest approach of the electron to plate B is nearest to
A) 16 mm.
B) 18 mm.
C) 20 mm.
D) 22 mm.
E) 24 mm.
Free
Multiple Choice
Q 28Q 28
In the figure, a proton is projected horizontally midway between two parallel plates that are separated by 0.50 cm. The electrical field due to the plates has magnitude 610,000 N/C between the plates away from the edges. If the plates are 5.60 cm long, find the minimum speed of the proton if it just misses the lower plate as it emerges from the field.
(e = 1.60 × 10-19 C, ε0 = 8.85 × 10-12 C2/N ∙ m2, mel = 9.11 × 10-31 kg)
Free
Short Answer
Q 29Q 29
A dipole with a positive charge of 2.0 μC and a negative charge of -2.0 μC is centered at the origin and oriented along the x-axis with the positive charge located to the right of the origin. The charge separation is 0.0010 m. Find the electric field due to this dipole at the point x = 4.0 m, y = 0.0 m.
(k = 1/4πε0 = 8.99 × 109 N ∙ m2/C2)
A) 0.56 N/C
B) -0.56 N/C
C) 0.28 N/C
D) -0.28 N/C
Free
Multiple Choice
Q 30Q 30
An electric dipole is made of two charges of equal magnitudes and opposite signs. The positive charge, q = 1.0 μC, is located at the point (x, y, z) = (0.00 cm, 1.0 cm, 0.00 cm), while the negative charge is located at the point (x, y, z) = (0.00 cm, -1.0 cm, 0.00 cm). How much work will be done by an electric field = (3.0 × 106 N/C)
To bring the dipole to its stable equilibrium position?
A) 0.060 J
B) 0.030 J
C) 0.00 J
D) 0.020 J
E) 0.12 J
Free
Multiple Choice
Q 31Q 31
An initially-stationary electric dipole of dipole moment = (5.00 × 10-10 C ∙ m)
Placed in an electric field
= (2.00 × 106 N/C)
+ (2.00 × 106 N/C)
. What is the magnitude of the maximum torque that the electric field exerts on the dipole?
A) 2.00 × 10-3 N ∙ m
B) 1.40 × 10-3 N ∙ m
C) 2.80 × 10-3 N ∙ m
D) 0.00 N ∙ m
E) 1.00 × 10-3 N ∙ m
Free
Multiple Choice
Q 32Q 32
An electric dipole consists of charges ±5.00 µC separated by 1.20 mm. It is placed in a vertical electric field of magnitude 525 N/C oriented as shown in the figure. The magnitude of the net torque this field exerts on the dipole is closest to
A) 2.02 × 10-6 N ∙ m.
B) 3.15 × 10-6 N ∙ m.
C) 2.41 × 10-6 N ∙ m.
D) 1.01 × 10-6 N ∙ m.
E) 1.21 × 10-6 N ∙ m.
Free
Multiple Choice