(a) Write names of any two conventional sources of energy.
(b) Write any two limitations in harnessing wind energy.

Hint: Conventional sources of energy are the resources of natural energy. Since they are present in the limited quantity, they are non-renewable sources of energy and they cannot be generated at the same speed which can sustain its consumption rate. They are being used for a long time.

Complete answer:
a.)Names of any two conventional sources of energy: - natural gas, oil, coal, and nuclear source of energy. Though they are in a finite amount but still they contribute the majority to the energy market.

b.)Following are some limitations in harnessing wind energy: -
i.)The initial cost (setting up of the wind mills and all) is very high.
ii.)There is the requirement of the high speed of the wind to generate the wind energy. The speed of the wind should not be less than the km/h.
iii.)Location of the land on which the wind mills are to be installed must be vast and mountainous where the speed of the wind is high.

Note:
Wind energy is a non-conventional source of energy, like this there are some more energy sources which are non-conventional. Non-conventional source of energy is the source of energy which is renewable. Some of the renewable sources of energy are wind, fuel cells, solar, biogas/biomass, tidal, geothermal energy.
The wind energy sometimes called “wind power” is used to generate mechanical power and electricity. The mechanical power can be used in different tasks like grinding grain or pimping water and with a generator we can convert this mechanical power into electrical power.