The energy of the sun is produced by?

Appeared in: UPPSC-2021

Explanation

The Sun's energy is generated by nuclear fusion, where lighter atomic nuclei combine to form a heavier nucleus, releasing energy.
Specifically, in the Sun's core, four hydrogen nuclei (protons) fuse through the proton-proton chain reaction to create one helium nucleus.
During this process, a small fraction of the mass is converted into a vast amount of energy, according to Einstein's equation E=mc².
This process requires extremely high temperatures (about 15 million °C) and pressures, which are present in the core of the Sun.

Option B: Oxidation is a chemical reaction (like burning) that releases far less energy per atom than nuclear reactions and could not sustain the Sun's output for billions of years.
Option C: While gravitational contraction provides the initial heat to start nuclear fusion in a protostar, it is not the long-term, sustained energy source for a stable star like the Sun.
Option D: Nuclear fission is the splitting of heavy atomic nuclei (like uranium). The Sun is primarily composed of light elements (hydrogen and helium), making fusion the dominant process.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Source of Solar Energy as background academic context rather than a clinical decision trigger.
This is a fundamental concept in physics and astronomy, not directly related to clinical nursing practice.
An understanding of nuclear processes provides a background for concepts like radiation (gamma rays from the sun) and its effects, which is relevant to medical fields like radiology and radiation safety.
What if the question was about energy production in human cells? The answer would be biological oxidation (cellular respiration), where glucose and other fuel molecules are broken down to produce ATP, the energy currency of the cell.

How to Approach the Question

Identify the core of the question: it asks for the energy source of the Sun.
This is a factual recall question from basic science (physics/astronomy).
Evaluate the options based on their definitions.
Recall that stars are powered by nuclear reactions.
Differentiate between the two main types of nuclear reactions: fusion (joining light nuclei) and fission (splitting heavy nuclei).
Since the Sun is made of light elements (mostly hydrogen), fusion is the logical process. Eliminate fission.

Concept Tested & Keywords

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Practise the full UPPSC-2021

Attempt every question from this paper in a timed mock, then review the full solution for each one.