A) The Electric field in free space is given by E= 20 cos(wt - 50x) ay Calculate F if m Hr = 3. B) Find the potential difference between point A (1,2,3) and B (3,2,4) due to infinite line charge of p₁-3nC/m along the z-axis. C

A point charge q = 1 nC is placed at the following position in the x-yplane: at (x, y) = (0, 3m). Calculate the magnitude of the electric field atthe point P: (x, y) = (0, 0).

(1 )Region one z>0 consist of dielectric medium (er=4) (2)Region two z<0 consist of perfect conductor. Determine D&E at point (3,2,-3) and point (2,-1,3), if the surface charge on the conductor is equal to 8nc/m?

In the early 1900's Robert Millikan discovered the peculiar property that charge came in little packets, no smaller than e = 1.602 x 10-19 C -- he had measured the charge of the electron. Here's (roughly) how he did it.  He removed an electron from an initially neutral droplet of oil with diameter 0.5 ??μm. In a vacuum, he positioned the droplet between two metallic plates separated by 6 mm and fiddled with the potential (voltage) across the plates until the droplet would hover against the force of gravity. Droplets of this size with +e charge would hover, but only for a particular voltage (otherwise they would sink or rise).  Given the parameters stated here, and the fact that the density of the oil was 831 kg/m3, what was the voltage that made the droplets hover? (give your answer with 0.1 V precision)