PLEASE ANSWER FAST, WILL GIVE BRAINLIEST AND 20 POINTS What causes the poles of the electromagnet in an audio speaker to repeatedly switch directions?

A. a metal striker that pulls on the magnet
B. a diaphragm that vibrates around the magnet
C. a current that rapidly switches direction
D. a device that opens and closes a circuit

How do we use the sumif formula (when dealing with different formats) ?

Create a class named majors that includes an enumeration for the six majors offered by a college as follows: acc, chem, cis, eng, his, phys. display the enumeration values for the user, then prompt the user to enter a major. display the college division in which the major falls. acc and cis are in the business division, chem and phys are in the science division, and eng and his are in the humanities division. save the file as majors.java.

When is a chart legend used a. all the time b. whenever you are comparing data that is the same c. whenever you are comparing multiple sets of data d. only for hand-drawn charts