Question

In a closed jar, air is kept at room temperature (25°C). Air heated at 60°C is inserted with a pipe with its mouth at the centre of the jar. Using a diagram show the direction of movement of the inserted air. Give reasons.


Please send the answer ASAP
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Answer 1

Height of the water column, h1=10+15=25cm

Height of the spirit column, h2=12.5+15=27.5cm

Density of water, ρ1=1g/cm3

Density of spirit, ρ2=0.8g/cm3

Density of mercury ρ=13.6g/cm3

Let h be the difference between the levels of mercury in the two arms.

Pressure exerted by height h, of the mercury column:

= ρhg

= h×13.6×g  (i)

Difference between the pressures exerted by water and spirit:

= ρ1h1g−ρ2h2g

= g(25×1−27.5×0.8)

= 3g  (ii)

Equating equations (i) and (ii), we get:

13.6 hg = 3g

h=0.221cm

Hence, the difference between the levels of mercury in the two arms is 0.221 cm.