Acapacitor is first connected to a 6 volt battery and then to a 12 volt battery. how would its capacitance change when connected to the higher voltage? a) it would increase. b) it would decrease. c) it would stay the same. d) there is no way to tell from the information given.

Correct sentence a) It would increase.

Explanation:

The capacity in farad (F) is directly proportional to the amount of electric charge that a capacitor can store for different values of voltage applied and stored between its plates. Mathematically this relationship can be represented by the following formula:

         C = Q V

From where:

C = Capacity (or capacitance), in farad (F).

Q = Amount of electric charge stored, in coulomb.

V = Potential difference, in volt, between the plates.

Therefore, by doubling the voltage of the battery connected to the capacitor (voltage difference on the capacitor plates), its capacitance will double.

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.