A solenoid of length 5 cm has a cross sectional area of 1 cm2 and has 300 uniformly spaced turns. The solenoid is wrapped in 180 turns of insulated wire resulting in a mutual inductance of:. A) 100 H
B) 1.4 x 10^-2 H
C) 11 H
D) 1.4 x 1^-3 H
E) 1.1 H

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.

the answer to this is proletariats.

hope this : )

could you add the photo?

explanation: