Problem 16: A +38 μC point charge is placed 36 cm from an identical +38 μC charge. A -1.5 μC charge is moved from point A to point B as shown in Fig. 17-47. What is the change in potential energy? B 14 cm 12 cm 24 cm FIGURE 17-47 38 μC 38 μC Problem 81. A

(a) Calculate the number of electrons in a small, electrically neutral silver pin that has a mass of 10.0 g. Silver has 47 electrons per atom, and its molar mass is 107.87 g/mol. (b) Imagine adding electrons to the pin until the negative charge has the very large value 1.00 mC. How many electrons are added for every 109 electrons already present?

Air breaks down and conducts charge as a spark if the electric field magnitude exceeds 3.00 106 V/m. (a) Determine the maximum charge Qmax that can be stored on an air-filled parallel-plate capacitor with a plate area of 2.00 104 m2. (b) A 75.0 F air-filled parallel-plate capacitor stores charge Qmax. Find the potential difference across its plates.

When a potential difference of 150. V is applied to the plates of an air-filled parallel-plate capacitor, the plates carry a surface charge density of 3.00 1010 C/cm2. What is the spacing between the plates?

A point charge of q=50108 C is placed at the center of an uncharged spherical conducting shell of inner radius 6.0 cm and outer radius 9.0 cm. Find the electric potential at (a) r = 4,0cm, (b) r = 8.0 cm, (c) r — 12.0 cm.

Two parallel plates 10 cm on a side are given equal and opposite charges of magnitude 5.0109 C. The plates are 1.5 mm apart. What is the potential difference between the plates?

(a) Find the electric potential, taking zero at infinity, at the upper right corner (the corner without a charge) of the rectangle in Figure P16.13. (b) Repeat if the 2.00-C charge is replaced with a charge of 2.00 C. Figure P16.13 Problems 13 and 14.

Three charges are situated at corners of a rectangle as in Figure P16.13. How much work must an external agent do to move the 8.00-C charge to infinity? Figure P16.13 Problems 13 and 14.

A particle with charge 1.60 1019 C enters midway between two charged plates, one positive and the other negative. The initial velocity of the particle is parallel to the plates and along the midline between them (Fig. P26.48). A potential difference of 300.0 V is maintained between the two charged plates. If the lengths of the plates are 10.0 cm and they are separated by 2.00 cm, find the greatest initial velocity for which the particle will not be able to exit the region between the plates. The mass of the particle is 12.0 1024 kg. FIGURE P26.48

Throughout a region, equipotential surfaces are given by z = constant. The surfaces are equally spaced with V = 100 V for z = 0.00 m,= 200 V for 0.50 m, V= 300 V for z = 1.00 m. What is the electric field in this region?