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When the electric field (E) is increased by 2 times the electrical energy density (meaning electrical energy per unit volume) @ increases by 2 times O decreases by 2 times O decreases by 4 times O increases by 4 times D Question 7 1p If the speed of light in a medium is 217.936,539 m/'s. Calculate the refractive index of the medium, (Write your answer till 2 decimal places and do not mention units in your answer and assume speed of light in vacuum is 300,000,000 m/s)