Question 10 of 10 Which feature of electromagnets makes them more useful than permanent

magnets in many modern technologies?

A. The current can be adjusted to control the strength of the

magnetic field.

B. Electromagnets are not dependent on a power supply.

C. Electromagnets cannot be turned on and off.

D. The strength of the magnetic field is more consistent in

electromagnets

Amichelson interferometer operating at a 600 nm wavelength has a 3.02-cm-long glass cell in one arm. to begin, the air is pumped out of the cell and mirror m2 is adjusted to produce a bright spot at the center of the interference pattern. then a valve is opened and air is slowly admitted into the cell. the index of refraction of air at 1.00 atm pressure is 1.00028.how many bright-dark-bright fringe shifts are observed as the cell fills with air?