Exam 23: The Electric Field

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 3.0-μC positive point charge is located at the origin and a positive point charge is located at Find the coordinates of the point where the net electric field strength due to these charges is zero.

A very long wire carries a uniform linear charge density of What is the electric field strength from the center of the wire at a point on the wire's perpendicular bisector? (ε₀ = 8.85 × 10^-12 C^2/N ∙ m²)

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 v_o = 2.0 × 10⁷ m/s, as shown in the figure. (e = 1.60 × 10^-19 C, ε₀ = 8.85 × 10^-12 C²/N ∙ m², m_el = 9.11 × 10^-31 kg) The velocity of the electron as it strikes plate B is closest to

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)

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?

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 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)

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)

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?

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?

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?

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)

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

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

In the figure, a proton is projected horizontally midway between two parallel plates that are separated by The electrical field due to the plates has magnitude between the plates away from the edges. If the plates are 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, m_el = 9.11 × 10^-31 kg)

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

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?

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/ . Plate B is located at y = -1.0 cm and carries a uniform surface charge density +2.00 μC/ . 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)

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?