An air stream having an enthalpy of 100 kJ/kgda, is flowing at 20 kgda/s. It is cooled by water at temperature $10^\circ C$ circulating in a cooling coil at a flow rate of 10.0 l/s. If the return temperature of water is $20^\circ C$, the enthalpy of the cooled air, in kJ/kgda, is ______.

(Specific heat of water: 4.18 $kJ/kg ^\circ C$; $kgda$: $kg$ of dry air).

With reference to Coward diagram, match the following in the context of exploitability of a mixture of 'normal air' and 'methane'.

A U-tube manometer is subjected to differential pressure as shown. If specific gravity of kerosene is 0.8, the value of $(P_1 - P_2)$, in Pa, is______.

The static pressure characteristic of a mine fan is as shown. If the mine resistance is $0.3 \, \text{N/s}^2 / \text{m}^8$ , the quantity generated by the fan, in $m^3/ \text{s}$, is ______.

In the context of ventilation plan symbols, match the following:

The semivariogram shown belongs to a bauxite deposit. The expected difference in the $Al_2O_3$ (%) values between two boreholes separated by a distance of 200 m is ______.

Match the following mechanical properties with the formulae

Copper grade distribution in an ore body has the probability density function, $f(x)$, as shown in the figure. The average grade of the deposit, in % Cu, is ______.

A person standing 50 m away from an HEMM experiences 90 dB sound pressure level. If the person moves to a new location that is 70 m away from the HEMM, the sound pressure level experienced by the person, in dB, becomes ______.

Out of the support categories given for an underground coal mine, identify the ‘active support’.