\(1\,cm\) ત્રિજ્યા ઘરાવતું પાણીનું બુંદ સમાન \(729\) નાનાં બુંદ્દોમાં તૂટી જાય છે.જો પાણીનું પૃષ્ઠતાણ \(75\,\,dyne/cm\) હોય તો પ્રથમ દશાંશ ચિહ્ન સુધી પૃષ્ઠ ઊર્જામાં થતો વધારો \(...\times 10^{-4}\,J\) થશે.\((\pi = 3.14\) આપેલ છે.)

A \(8.5\)
B \(8.2\)
C \(7.5\)
D \(5.3\)

Verified Solution

Answer & Solution

Correct Answer

(C) \(7.5\)

Step-by-step Solution

Detailed explanation

Initial surface energy \(= TA\) Where \(T\) is surface tension and \(A\) is surface area \(U _{ i }=\left(\frac{75 \times 10^{-5}}{10^{-2}} \frac{ N }{ m }\right) \times\left[4 \pi\left(1 \times 10^{-2}\right)^{2}\right]\)…

Apply the relevant identity from the chapter and substitute the values established in the previous step, keeping the original constraint in view.

Use the simplified expression to isolate the unknown, then plug the result back into the question setup to confirm the working is internally consistent.

Cross-check against a boundary or limiting case. Both the dimensional balance and the qualitative behaviour at the extreme should agree with the candidate answer.

Combine the steps above to identify the correct option. The remaining choices each fail at least one of the consistency, dimensional, or boundary checks.

Same subject

Explore more questions on app

From JEE Mains

Explore more questions on app