When liquid medicine of density `rho` is to be put in the eye, it is done with the help of a dropper. As the bylb on the top of the dropper is pressed. A drop frons at the opening of the dropper. We wish to estimate the size of the drop.
We first assume that the drop formed at the opening is spherical because that requires a minimum increase in its surface energy, To determine the size. We calculate the net vertical force due to the surface tension T when the radius of the drop is R. when this force become smaller than the weight of the drop the drop gets detached from the dropper.
If the radius of the opening of the dropper is r, the vertical force due to the surface tension on the drop of radius`R`(assuming `rlt ltR)` is

Options

A. `2pi rT`
B. `2pi RT`
C. `(2pir^(2)T)/(R)`
D. `(2piR^(2)T)/(r)`

Explanation

To solve the problem of estimating the size of a drop formed at the opening of a dropper, we will analyze the forces acting on the drop due to surface tension and weight.

### Step-by-Step Solution:

1. **Understanding the Geometry**:
- The drop formed at the opening of the dropper is assumed to be spherical.
- Let the radius of the drop be \( R \) and the radius of the opening of the dropper be \( r \).

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