TG EAMCET 3 May 2025 Shift 1 Paper

To find the work done to make a soap bubble bigger, we use the formula:
W=2T⋅∆A
Step 1: Find Change in Surface Area for W1
The surface area of a sphere is 4πr2. When the radius goes from r to 2r, the change in area is:
∆A=4π(2r)2−4πr2
This simplifies to:
=16πr2−4πr2=12πr2
Step 2: Find Work Done W1
Plug the change in area into the work formula:
W1=2T⋅12πr2=24πTr2
Step 3: Find Change in Surface Area for W2
Now, change the radius from 2r to 3r :
‌∆A=4π(3r)2−4π(2r)2
‌=36πr2−16πr2=20πr2
Step 4: Find Work Done W2
Plug in this change in area:
W2=2T⋅20πr2=40πTr2
Step 5: Ratio W1:W2
W1:W2=24:40=3:5