The height of mercury column in a barometer in a Calcutta laboratory was recorded to be 75 cm. Calculate this pressure in SI and CGS units the following data, Specific gravity of mercury = 13.6, Density of `water = 10^3 kg/m^3, g=9.8 m/s^2` at Calcutta. Pressure `=h rho g` in usual symbols.

Answer

A, B, C, D

Explanation

Height, `h= 75cm = 0.75m` Density of mercury `= 13600 kg/m^3` `g= 9.8 m/sec^2` Pressure `= hrhog` `= (0.75) xx 13600 xx 9.8 = 10 xx 10^4 N/m^2` (approximetely) In C.G.S. units `P= 10 xx 10^4 N/m^2 = (10 xx 10^4 xx 10^5 dyne)/(10^4 cm^2) = 10 xx 10^5 dyne/cm^2`