The lower and upper fixed points of a mecury-in-glass thermometer are marked Y and 180mm respectively. On a particular the mecury meniscus in the thermometer rises to 45mm. If the corresponding reading on a scale is 10o, calculate the value of Y.
- 4mm
- 18mm
-
30mm
- 135mm
- 450mm
The correct answer is: C
Explanation
by interpolation,
\(\frac{100 - 0}{10- 0} = \frac{180 - y}{45 - y}\)
\(\frac{100}{10} = \frac{180 -y}{45 - y }\)
450 - 10y = 180 - y
- 9y = - 270
y = 30mm