Q.

An air bubble of volume 1 cm3 rises from the bottom of a lake 40 m deep to the surface at a temperature of 12°C. The atmospheric pressure is 1×105 Pa, the density of water is 1000 kg/m3 and g=10 m/s2. There is no difference of the temperature of water at the depth of 40 m and on the surface. The volume of the air bubble when it reaches the surface will be                [2023]

1 cm3  
2 cm3  
3 cm3  
4 cm3  

Ans.

(3)

P=P0+ρgh=105 Pa+103×10×40=5×105 Pa

At T is constant, PV=P0V0

5×105 Pa×1 cm3=105 Pa×V0V0=5 cm3