64 identical drops each charged upto potential of 10 mV are combined to form a bigger drop. The potential of the bigger drop will be_____mV.

Question

Accepted Answer

Correct answer: 160. (160) The formula to calculate the potential (V") of each tiny drop is given by V=k qr ...(a) When all the drops forms the bigger drop the radius of the new drop (r’) can be calculated as follows: Volume of big drop = 64 x volume of each tiny drop ⇒ 43 r '^3=64 43 r^3 ⇒r '=4r So, the potential of the new big drop (V’) can be written as V '=k 64qr ' =k 64q4r =16k qr ...(b) Divide equation (b) by equation (a) and simplify to obtain the potential of the new drop. V 'V= 16k qrk qr ⇒V '=16V...(c) Substitute the value of the known parameter into equation (c) to calculate the required value of the potential for the new drop. v'=16 x 10 mV =160 mV

$64 identical drops each charged upto potential of 10 mV are combined to form a bigger drop. The potential of the bigger drop will be_____mV.$

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