Electric charge can accumulate on an airplane in flight. You may have observed needle-shaped metal extensions on the wing tips and tail of an airplane. Their purpose is to allow charge to leak off before much of it accumulates. The electric field around the needle is much larger than the field around the body of the airplane and can become large enough to produce dielectric breakdown of the air, discharging the airplane. To model this process, assume that two charged spherical conductors are connected by a long conducting wire and a charge of 62.0 µC is placed on the combination. One sphere, representing the body of the airplane, has a radius of 6.00 m, and the other, representing the tip of the needle, has a radius of 2.00 cm. (a) What is the electric potential of each sphere? r = 6.00 m: V r = 2.00 cm: V (b) What is the electric field at the surface of each sphere? r = 6.00 m: magnitude V/m direction ---Select--- r = 2.00 cm: magnitude V/m direction ---Select---

In the early 1900s, Robert Millikan used small charged droplets of oil, suspended in an electric field, to make the first quantitative measurements of the electron’s charge. A 0.70-μm-diameter droplet of oil, having a charge of +e, is suspended in midair between two horizontal plates of a parallel-plate capacitor. The upward electric force on the droplet is exactly balanced by the downward force of gravity. The oil has a density of 860 kg/m3, and the capacitor plates are 5.0 mm apart. What must the potential difference between the plates be to hold the droplet in equilibrium?

A Geiger-Mueller tube is a radiation detector that consists of a closed, hollow, metal cylinder (the cathode) of inner radius ra and a coaxial cylindrical wire (the anode) of radius (see figure below) with a gas filling the space between the electrodes. Assume that the internal diameter of a Geiger-Mueller tube is 1.95 cm and that the wire along the axis has a diameter of 0.190 mm. The dielectric strength of the gas between the central wire and the cylinder is 1.25 x 106 V/m. Use the equation ain 2πrle= to calculate the maximum potential difference that can be applied between the wire and the cylinder before breakdown occurs in the gas. €0 Anode Cathode 148 X Your response differs from the correct answer by more than 10%. Double check your calculations. V Need Help? Read It

An air-filled capacitor is charged, and then a dielectric is inserted. As a result, there is an induced charge on the dielectric. What is the difference between induced charge and free charge? Option 1: Induced charge is the charge that resides on the surface of the dielectric, while free charge is the charge that is free to move within the dielectric. Option 2: Induced charge is the charge that is created by the electric field of the capacitor, while free charge is the charge that is already present in the dielectric. Option 3: Induced charge is the charge that is attracted to the oppositely charged plates of the capacitor, while free charge is the charge that is repelled by the plates. Option 4: There is no difference between induced charge and free charge.

Two identical balls each having a density pare suspended from a common point by two insulating strings of equal length. Both the balls have equal mass and charge. In equilibrium, each string makes an angle with the vertical. Now, both the balls are immersed in a liquid. As a result, the angle does not change. The density of liquid is o. Find the dielectric constant of the liquid.

A spherical capacitor is composed of two concentric conducting spheres, one of radius a and the other of radius c (c > a). In addition, between the two conductors there is a spherical shell of dielectric material (relative permittivity/relative dielectric constant ) with inner radius b (c > b > a) and outer radius c. The charge on the inner conductor is +Q. The charge on the outer conductor is -Q. (a) Make a sketch of the situation, indicating the relevant dimensions. (b) Determine the magnitude of the electric field E at radius r for a < r < b. (c) Determine the magnitude of the electric field E at radius r for b < r < c. (d) What is the (induced) surface charge density on the inner surface of the dielectric. (e) Sketch the radial component of the electric field versus r . (f) Sketch the electrostatic potential versus r . (g)Calculate the potential difference between the conductor at r = a and that at r = c. (h) What is the capacitance of this capacitor?