2. A grounded spherical conductor is on an insulating stand. A positively charged rod is brought close to the sphere but does not touch the sphere, as shown above. The rod is moved far away and then the grounding wire is removed. Which of the following describes the resulting charge on the sphere?
(C) No net charge, but it is polarized with positive charges on the left side of the sphere
(D) No net charge, but it is polarized with negative charges on the left side of the sphere
(E) No net charge and no polarization
1. Students design an experiment to determine the unknown dielectric constant kappa kappa of a plastic material. A capacitor is created using two square aluminum plates of side length s=30cm that are separated by a distance d=1.0mm. This capacitor is placed in a circuit with an ideal 6.0-volt battery, a resistor of resistance R=500Ω, voltmeter V, and an open switch S, as shown above. A 1.0 millimeter thick piece of plastic is inserted between the aluminum plates. The distance x that the plastic is inserted between the plates can be varied, and the voltmeter is used to measure the potential difference Vc across the capacitor. The switch is closed, and readings from the voltmeter are recorded as a function of time t. The data are plotted to create the graph shown below.