You are performing an experiment that requires the highest possible energy density in the interior of a very long solenoid. which of the following increases the energy density? (select all that apply.) increasing only the length of the solenold while keeping the turns per unit lengh flxed increasing the number of turns per unit length on the solenold increasing the cross-sectional area of the solenoid none of these increasing the current in the solenoid

no sign of dia of fuel cell

speed of light in vacuum is 300,000 km/s

speed of light in other mediums is given by the expression v = c/n, where c is the speed of light in vacuum and n is the refractive index of medium.

for the first medium v = 200,000 km/s

  so, refractive index of medium = 300000/200000 = 1.5

    1.5 refractive index is usually for glass. so first medium is glass.

for the second medium v = 250,00 km/s

so, refractive index of medium = 300000/250000 = 1.2

    1.2 refractive index is usually for water. so second medium is water.

for the third medium v = 0 km/s

so, refractive index of medium = 300000/0 = ∞

    ∞ refractive index is usually for opaque mediums. so third medium is opaque medium.