có 3 dây dẫn thẳng song song ,vuông góc với mặt phẳng hình vẻ, có dòng diện I1 I2 I3 chạy qua như hinh ve , Dòng I1 I2 được giữ chặt , Dong I3 có xu hướng

Um ya

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ya

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see yu

continuous conducting path for current, power supply

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.