What can be done to remove a magnetic force around an electromagnet made of a coiled copper wire wrapped around an iron bar and connected to a
power source?
O A. Uncoil the wire.
B. Remove the iron bar.
C. There is always a small magnetic force around the wire.
D. Stop the current.

The content of manganese (mn) in steel was determined spectrophotometrically and with the use of the standard addition method. an unknown sample of mn from a digested steel sample gave an absorbance of 0.185 when analyzed spectrophotometrically. when 5.00 ml of solution containing 95.5 ppm mn was added to 50.0 ml of the unknown steel solution (digested sample), the absorbance was 0.248. calculate the concentration, in parts-per-million (ppm), of mn in the digested steel sample solution.