An electromagnetic wave has a wavelength of 6.2 x 10^14 m. What is the frequency of the wave?

A. 2.0 x 10^6 Hz
B. 4.8 x 10^-7 Hz
C. 1.8 x 10^24 Hz
D. 5.3 x 10^-22 Hz
I got B..?

When the currents in two parallel metal conductors are in the same direction, the conductors ____ each other.
A. attract
B. repel
C. do no exert any force
D. exert forces that are perpendicular to
I got D..?

3 answers

first right,second wrong.
   6.  A  current-‐carrying  conductor  is  kept  at  right  angles  to  the  direction  of  a  magnetic  field.  What  happens  to  the  force  acting  on  the  wire  if  the  strength  of  the  magnetic  field  doubles?  
 A  current-‐carrying  conductor  is  kept  at  right  angles  to  the  direction  of  a  magnetic  field.  What  happens  to  the  force  acting  on  the  wire  if  the  strength  of  the  magnetic  field  doubles?