How do home computer scanners generally use electromagnetic waves? O A. They change information received from sound waves into electromagnetic waves.
OB. They gather information from reflected and absorbed waves.
O C. They receive microwaves that are emitted by natural objects.
O D. They use X-rays that penetrate most objects. SUBMIT​

Four point charges each having charge q are located at the corners of a square having sides of length a. find symbolic expressions for the following. (a) the total electric potential at the center of the square due to the four charges (use any variable or symbol stated above along with the following as necessary: ke.) vtotal= (b) the work required to bring a fifth charge p from infinity to the center of the square (use any variable or symbol stated above along with the following as necessary: w=