Question

The lower end of a capillary tube of radius r is placed vertically in water, then water in the capillary , heat evolved as

Answer 1

The capillary action rise due to surface tension is

$h=\frac{2s_t}{r\rho g}$

where $s_t=s_0(1+\alpha t)$ when $s_t\&s_0$ are temperature at $7^o$ & $0^{o}C$

$\therefore \frac{mchr\rho g}{2s_0}=mc+mc\alpha t$ when in is man C is specite heat water

$mc[\frac{hr\rho g}{2s_0}-1]=\alpha \times mct$

heat esolved = $\frac{mc}{\alpha }[\frac{hr\rho g}{2s_0}-1]$