Question

Thermometer s sensitivity ?

Why does the liquid in the think thermometer move further than the liquid in the thick tune in the same temperature and same atmospheric temperature?

Answer 1

Thin thermometer means cross sectional area of the capillary tube is smaller than that of a thick thermometer,so on heating,the rise in level of mercury is more in case of a thin thermometer,than a thick thermometer.

Suppose, on heating mercury by `x` degree, it's new volume becomes `V`

Now,for a thin thermometer `V = A×l` (where, `A` is the cross sectional area and `l` is length ,that indicates the rise of mercury in the capillary tube)

And,for a thick thermometer, `V = A'×l'` (where, `A'` is the cross sectional area and `l'` is the increase in mercury level)

Now, we can write,

`l/(l') =(A')/A`

`As, A'>A`

So, `l>l'`

So,increase in the level of mercury in a thin thermometer is more than that of a thick thermometer.

And it is the reason why thin thermometer is more sensitive than thick thermometer.