Which of the following lists the composition of the earth’s outer core?
a. calcium, potassium
b. silicon, aluminum, calcium, sodium and potassium
c. iron, nickel
d. oxygen, magnesium, iron, aluminum, and calcium

The primary benefit of taking into account a child's interests while selecting exercise activities is that the child will a. play more willing with others b. succeed at their favorite activity c. allow parents to relax afterwards d. gain motivation to exercise select the best answer from the choices provided.

What is the function of the commutator in a dc motor? a. to spin the magnet b. to change direct current into alternating current c. to change alternating current into direct current d. to spin the wire coil

Which graph best represents the relationship between the electric current and the rate at which a magnet is turning inside an electric generator?