A parallel-plate capacitor under the key of a keyboard has circular plates that are separated by 0.0500 mm and filled with a dielectric with k = 4.00. When the potential difference across the plates is 5.00 V , the magnitude of the charge on each plate is 8.897 pC. What is the radius of one of the plates? When the key is pressed, the distance between the plates decreases, increasing the capacitance to 1.85 pF. What is the separation between the plates when the key is pressed?

A 7.44 µF isolated capacitor is constructed with Teflon, having a dielectric constant of 2.10, between the plates. The capacitor is initially charged to 1.34 volts, and then the Teflon is removed. After removing the Teflon, what is the potential difference across the capacitor plates?

A parallel-plate capacitor has capacitance C0 = 8.00 pF when there is air between the plates. The separation between the plates is 1.20 mm. Express your answer with the appropriate units. Part A: What is the maximum magnitude of charge that can be placed on each plate if the electric field in the region between the plates is not to exceed 3.00×104 V/m? Part B: A dielectric with K = 2.70 is inserted between the plates of the capacitor, completely filling the volume between the plates. Now what is the maximum magnitude of charge on each plate if the electric field between the plates is not to exceed 3.00×104 V/m?

Consider a spherical capacitor in which the inner and the outer spheres have radii of (a) and (b), respectively. The capacitor is charged to Q=10.0 nC using a 10.0 V battery. How can you increase the capacitance? Increase the charge on the capacitor. Decrease the potential difference between the conducting spheres. Increase the radius of the outer sphere. The values of (a) and (b) must be given to answer the question. None of the above. SAMSUNG