Correct Answer - Option 4 : 4 bar or 40.77 m of water or 2.99 m of Hg

__Concept:__

The intensity of pressure is given by P = ρ × g × h

Where, ρ = density of the fluid, and h = is the height of liquid column

1 bar = 10^{5} pa

__Calculation:__

Given, specific gravity of mercury = 13.6, Pressure = 400 KPa

So 400 KPa = 400 × 10^{3} Pa

\(400\;KPa = \frac{{\left( {400 \times {{10}^3}} \right)}}{{{{10}^5}}}\;bar = 4\;bar\)

**Now pressure in terms of mercury column**

∵ P = ρ × g × h

400 × 10^{3} = 13.6 × 1000 × 9.81 × h

\(h = \frac{{400}}{{13.6 \times 9.81}} = 2.99\;m\)

i.e. 2.99 m of Hg

**Again Pressure in terms of water column **

∵ P = ρgh

400 × 10^{3 }= 1000 × 9.81 × h

h = \(\frac{{400}}{{9.81}} = 40.77\;m\)

i.e. 40.77 m of water