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

Write code using c . (take input from user) calculate the size of a given file in kbs. in this task you will complete the function with the following prototype: float get_file_size(char * filename); the function takes the file name (address to the start of a null terminated character array) as input. the function should then open the file and find the number of bytes it contains till eof. the number of bytes divided by 1024 will give the size in kbs. if the file cannot be opened the function should return -1.

How can a user open a blank presentation? 1.on the file menu, click new, and then click recent templates 2.on the file menu, click new, and then click blank presentation 3. on the view menu, click templates, and then click recent templates 4. on the view menu, click samples, and then click blank presentation

Write a program that reads a file consisting of students’ test scores in the range 0–200. it should then determine the number of students having scores in each of the following ranges: 0–24, 25–49, 50–74, 75–99, 100–124, 125–149, 150–174, and 175–200. output the score ranges and the number of students. (run your program with the following input data: 76, 89, 150, 135, 200, 76, 12, 100, 150, 28, 178, 189, 167, 200, 175, 150, 87, 99, 129, 149, 176, 200, 87, 35, 157, 189.)