Question

Which of the following are the primary sources of usable energy? A. Solar energy B. Geothermal energy C. Fossil fuels D. Hydro/wind energy E. Lunar energy

• A. A, B and C only
• B. A, B, C and D only
• C. A, B and E only
• D. A, B, D and E only

Hint:

Primary energy sources include solar, geothermal, fossil fuels, nuclear, and hydro/wind. Lunar (tidal) energy exists but is minor.

Answer 1

The Correct Option is B

Step 1: Concept
Primary sources of usable energy.

Step 2: Meaning
Primary energy sources are those that provide energy directly from naturally occurring processes without requiring further energy conversion from another primary source.

Step 3: Analysis
Solar (A), Geothermal (B), Fossil fuels (C), Hydro/wind (D): All are recognised, commercially exploited primary energy sources.
Lunar energy (E): Tidal energy is derived from lunar gravity and is technically usable, but is not currently a major practical primary source and is often omitted from standard classifications.

Step 4: Conclusion
Solar, geothermal, fossil fuels, and hydro/wind are the primary sources of usable energy. Final Answer: (B)