An air-filled capacitor consists of two parallel plates, each with an area of 7.60 cm2, separated by a distance of 1.70 mm. A 23.0-V potential difference is applied to these plates. (a) Calculate the electric field between the plates.   kV/m (b) Calculate the surface charge density.   (c) Calculate the capacitance.   (d) Calculate the charge on each plate.

Four particles are positioned on the rim of a circle. The charges on the particles are +0.500 C, +1.50 C, 1.00 C, and 0.500 C. If the electric potential at the center of the circle due to the +0.500 C charge alone is 4.50 104 V, what is the total electric potential at the center due to the four charges? (a) 18.0 104 V (b) 4.50 104 V (c) 0 (d) 4.50 104 V (e) 9.00 104 V

A parallel-plate capacitor with capacitance C0 stores charge of magnitude Q0 on plates of area A0 separated by distance d0. The potential difference across the plates is V0. If the capacitor is attached to a battery and the charge is doubled to 2Q0, what are the ratios (a) Cnew/C0 and (b) Vnew/V0? A second capacitor is identical to the first capacitor except the plate area is doubled to 2A0. If given a charge of Q0, what are the ratios (c) Cnew/C0 and (d) Vnew/V0? A third capacitor is identical to the first capacitor, except the distance between the plates is doubled to 2d0. If the third capacitor is then given a charge of Q0, what are the ratios (e) Cnew/C0 and (f) Vnew/V0?

A uniform electric field of magnitude 325 V/m is directed in the negative y direction in Figure P20.1. The coordinates of point are (0.200, 0.300) m, and those of point are (0.400, 0.500) m. Calculate the electric potential difference using the dashed-line path. Figure P20.1

(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.

In Active Figure 20.8a, take q1 to be a negative source charge and q2 to be the test charge. (i) If q2 is initially positive and is changed to a charge of the same magnitude but negative, what happens to the potential at the position of q2 due to q1? (a) It increases. (b) It decreases. (c) It remains the same. (ii) When q2 is changed from positive to negative, what happens to the potential energy of the two-charge system? Choose from the same possibilities.

Figure P26.80 shows a wire with uniform charge per unit length = 2.25 nC/m comprised of two straight sections of length d = 75.0 cm and a semicircle with radius r = 25.0 cm. What is the electric potential at point P, the center of the semicircular portion of the wire? FIGURE P26.80

A uniformly charged insulating rod of length 14.0 cm is bent into the shape of a semicircle as shown in Figure P20.29. The rod has a total charge of 7.50 C. Find the electric potential at O, the center of the semicircle. Figure P20.29

(a) Regarding (lie Earth and a cloud layer 800 m above the Earth as the plates of a capacitor, calculate the capacitance of the Earth-cloud layer system. Assume the cloud layer has an area of 1.00 km2 and the air between the cloud and the ground is pure and dry'. Assume charge builds up on the cloud and on the ground until a uniform electric field of 3.00 106 N/C throughout the space between them makes the air break down and conduct electricity as a lightning bolt, (b) What is the maximum charge the cloud can hold?

A parallel-plate capacitor has square plates that are 8.00 cm on each side and 3.80 mm apart. The space between the plates is completely filled with two square slabs of dielectric, each 8.00 cm on a side and 1.90 mm thick. One slab is Pyrex glass and the other slab is polystyrene. If the potential difference between the plates is 86.0 V, find how much electrical energy can be stored in this capacitor.