Which statement is true of magnets? a. elecromagnets are generally weaker than permanent magnets. b. earth is an electromagnet. c. a magnet always has a north pol, and may or may not also have a south pole. d. permanent magnets can be turned off.

The answer would be B. Earth is an electromagnet.

The Earth is a giant electromagnet. It's electromagnetic field is generated from the currents of electricity coming from molten metal flowing in the outer core of our Earth. The heat from the inner core causes convection and that is how electric current flows within Earth.

find the surface area of the sphere to the nearest square unit. use a calculator.

a. 254 in.2

b. 64 in.2

c. 127 in.2

d. 1,018 in.2