1. Solve any five

(a) State the various direct applications of solar energy.

(b) Describe the potential of renewable energy sources in India.

(c) State the site selection criteria for locating wind mills.

(d) Define solar constant, air mass, solar altitude angle, angle of incidence.

(e) State atleast five sites/places available in India for harnessing rising geothermal energy.

(f) Describe working of Fixed dome type biogas plant.

2(a) Describe construction and working of wind energy conversion system with neat sketch.

2(b) Describe working of solar pumping system with neat sketch.

2(c) Describe working of single basin tidal power plant.

3(a) If the angle of declination on a particular day was +18.25$^\circ$C, which is the date assuming leap year? Calculate the day length on May 02$^{nd}$ on a surface sloping southward at an angle of 40$^\circ$C at a place of 19$^\circ$07' N latitude and 72$^\circ$51' longitude,

3(b) Which factors affect the rate of production of biogas? State their ideal values/range for maximum biogas production?

3(c) State the advantages and disadvantages of geothermal energy.

4(a) State and explain the design consideration in wind turbine designs.

4(b) Describe working of wave energy conversion system with neat sketch.

4(c) State various parameters which affect performance of solar collectors. State limitations of flat plate collectors.

5(a) Following observation were recorded from a test on Biogas system:

C.V. of methane: $28.5MJ/m^3$;

Burner efficiency: 60%;

Number of cows: 8;

Retention period: 20days;

Temperature of fermentation: $30^\circ$;

Dry matter collected per cow per day; 2Kg;

Density of dry matter in the fluid in the digester: $50Kg/m^3$;

Biogas yield: $02m^3$ per Kg of dry input;

Methane proportion in the biogas: 0.7. Determine the volume of digester and power available from biogas digester.

5(b) Describe working of Claude cycle OTEC system with neat sketch.

5(c) Describe working of Central tower receiver using Heliostat mirror with neat sketch.

6(a) Calculate the rotor radius of multi-blade wind machine operating at a design speed of 25 kmph. The machine operates a water pump having a capacity of 5.1$m^3/hr$ and a lift of 9m. The following data is given:

Density of water = $996Kg/m^3$; efficiency of water pump = 0.6; efficiency of transmission from rotor to pump = 0.9; $C_p=0.31;\lambda=0.75;$ density of air is 1.2$Kg/m^3$.

6(b) State the classification of fuel cells in brief and describe working of molten carbonate fuel cell with neat sketch.

6(c) Describe working of low temperature binary fluid system with neat sketch.