The gravitational pull of Moon on spinning Earth causes the rise and fall in the sea level. This is called high tide and low tide and the difference in water levels between high and low tides gives us tidal energy.

Accidents involving nuclear power plants are disastrous and have very grave consequences.

Sunrays are focused at a point using concave reflectors. The solar radiations falling on the concave reflectors are focused at a point. Thus, large amount of heat radiations concentrated at a point increases the temperature of that point to a high value. Hence, option (1) is correct.

The most powerful energy source, if utilized properly, is nuclear energy as it is the result of bombarding uranium nuclei by neutrons. Hence, option (3) is correct.

Hydro energy is not a form of energy obtained from the sea.

Geothermal energy is not influenced by the sun. The source of geothermal energy is the heat present in the earth's crust.

In a nuclear fission reaction, heavier nucleus breaks up into lighter nuclei and releases energy.

Green house is a glass structure used to protect the plants from cold as it is a property of glass. Hence, option (3) is correct.

Energy crisis can be solved by utilising geothermal energy, nuclear energy and solar energy. So, option (4) is correct.

Following are the major drawbacks of a nuclear power plant: (i)   It contaminates environment with hazardous radiations. (ii)  It is very costly to set up. (iii) It uses uranium, which is scarcely available and not in abundance. Since all these are the drawbacks of a nuclear power plant, then option (4) is correct.

Solar cooker is used to cook food on a sunny day because it requires a temperature of about 100^o C to 140^oC. Hence, option (2) is correct.

Geothermal energy is produced due to geological changes. Hence, option (3) is correct.

The following are the drawbacks of solar cell panel: (i)    It is costly to set up. (ii)   It is a low power source. (iii)  It is associated with pollution. Option 4 is the correct answer. 

If energy changes from useful to useless form, then energy crisis occurs. Hence, option (3) is correct.

Hydropower is a renewable source of energy. Hence, option (3) is correct.