The material of a wire has a density of 1.4 g / cm 3 . If it is not wetted by a liquid of surface tension 44 dyne/cm, then the maximum radius of the wire which can float on the surface of liquid is

Question

The material of a wire has a density of 1.4 g / cm 3 . If it is not wetted by a liquid of surface tension 44 dyne/cm, then the maximum radius of the wire which can float on the surface of liquid is (A)  (10/28)cm  (B)  (10/14)cm  (C)  (10/7)cm  (D)  0.7cm

Tardigrade Admin · Accepted Answer

2 T=π r2 l d × g r =√((2 T/π d g))=√(2 × 44 × 7/22 × 1.4 × 980) =(1/7) cm =(10/7) mm

Q. The material of a wire has a density of $1.4 g / c m^{3} .$ If it is not wetted by a liquid of surface tension $44$ dyne/cm, then the maximum radius of the wire which can float on the surface of liquid is

$\frac{10}{28} c m$

$\frac{10}{14} c m$

$\frac{10}{7} c m$

$0.7 c m$

$2 T = π r^{2} l d \times g$
$r = (\frac{2 T}{π d g}) = \frac{2 \times 44 \times 7}{22 \times 1.4 \times 980}$
$= \frac{1}{7} c m = \frac{10}{7} mm$

Q. The material of a wire has a density of 1.4g/cm3. If it is not wetted by a liquid of surface tension 44 dyne/cm, then the maximum radius of the wire which can float on the surface of liquid is

2810​cm

1410​cm

710​cm

0.7cm