In an electromagnet, what produces the magnetic field? A. Electric charges moving through a conducting wire.

B. Electric charges moving through the metal core.

C. The metal core within a coil of wire.

D. The magnetic field of a permanent magnet.

The sun’s mass is 2.0×10^ 30 kg, its radius is 7.0×10 5 km, and it has a rotational period of approximately 28 days. if the sun should collapse into a white dwarf of radius 3.5×10 3 km, what would its period be if no mass were ejected and a sphere of uniform density can model the sun both before and after?

The velocity of sound wave in air at 35°c is 353m/s, calculate the velocity of sound at 46°c

What surface does the epithelial tissue cover? a. the surface of the body b. lines internal organs c. forms many glands d. all of the above