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.

see the picture for the vector

the magnitude of the vector by pythagorean theorem

r = √( (-10)^2 + (3)^2 ) = √109

magnitude = √109 units

the direction angle between vector and x-axis is

tan^(-1)(3/10) = 16.699

so the direction is approximately 16.7 degrees north of west