Question

The upper and lower fixed points of a faulty mercury thermometer are $210^{\circ} F$ and $34^{\circ} F$ respectively. What temperature read by this thermometer would be correct?

• A. $22^{\circ} F$
• B. $80^{\circ} F$
• C. $100^{\circ} F$
• D. $122^{\circ} F$

Answer 1

Answer: (D)

Let reading of faulty thermometer and correct thermometer is $T^{\circ} F$
$\Rightarrow \frac{T-34}{210-34} =\frac{T-32}{180}$
$\Rightarrow 180 T-6120 =176 T-5632$
$\Rightarrow 4 T =488$
$\Rightarrow T=122^{\circ} F$