The coefficient of volumetric expansion of mercury is 18×10−5/o C. A thermometer bulb has a volume 10−6 m3 and cross section of stem is 0.004 cm2. Assuming that bulb is filled with mercury at 0ºC then the length of the mercury column at 100ºC is
4.5 cm
V=V0(1+γ△θ)⇒ Change in volume
V−V0=△V=A.△l=V0γ△θ
⇒△l=V0γ△θA=10−6×18×10−5×(100−0)0.004×10−4
=45×10−3 m=4.5 cm