A long, thin straight wire with linear charge density ? runs down the center of a thin, hollow metal cylinder of radius R. The cylinder has a net linear charge density

2?.

Assume ? is positive. Find expressions for the electric field strength. In what direction does the electric field point in each of the cases? (Use any variable or symbol stated above along with the following as necessary: r and ?0.)

(a) inside the cylinder, r < R

Magnitude E =

Direction=

(b)outside the cylinder, r > R

Magnitude E=

Direction=

Astudent is given an assignment to demonstrate diffraction. he takes a photograph of a straw in a glass of water. the straw appears bent at the water level. which best describes this example? a) this is a good example of diffraction. b) this is an example of dispersion and not diffraction. c) this is an example of refraction and not diffraction. d) this is an example of reflection and not diffraction.

What component of earth’s atmosphere exists entirely as a result of photosynthesis?

Ametal ring 4.20 cm in diameter is placed between the north and south poles of large magnets with the plane of its area perpendicular to the magnetic field. these magnets produce an initial uniform field of 1.12 t between them but are gradually pulled apart, causing this field to remain uniform but decrease steadily at 0.240 t/s . (a) what is the magnitude of the electric field induced in the ring? (b) in which direction (clockwise or counterclockwise) does the current flow as viewed by someone on the south pole of the magnet?