By what factor does the speed of light increases when light enters from glass to air

throught the medium Light travels at approximately 300,000 kilometers per second in a vacuum, which has a refractive index of 1.0, but it slows down to 225,000 kilometers per second in water (refractive index of 1.3; see Figure 2) and 200,000 kilometers per second in glass (refractive index of 1.5)

Explanation:

iron would move it is magnetic there is a mag field around the current in the wire