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64 small drops of water having the same charge and same radius are combined to form one big drop.The ratio of capacitance of big drop to a small drop is :
a)4:1
b)1:4
c)2:1
d)1:2Asked by sonali 4 months ago
Answers (1)
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For a spherical capacitor, the capacitance C is:
Here R is the radius of the sphere. As you can see, the capacitance is proportional to R.
Let us say the initial radius of each of the small drops is r. Then, the volume of the large drop is (4/3)(?)r3 x 64 = (4/3)(?)R3 where R is the volume of the new, large sphere.
Therefore, R = 4r. Therefore the capacitance of the larger drop is 4 times that of the initial small drop. So, the answer is a).