What type of energy is utilized by a sailing boat?

Name two combustible components of biogas.

How is the slurry left over after the generation of biogas in a biogas plant used?

Which process is used to harness nuclear energy these days? Explain it briefly.

Name the major fuel component of biogas. What are its other combustible components? Draw a simple labelled diagram of a fixed dome type biogas plant. What is the use of the residual slurry and why?

What is hydroelectricity? Explain the basic principle involved in the generation of this energy.