Introduction to the Universe

The chapter Universe in NEET Physics deals with astronomy and cosmology, explaining the structure, evolution, and dynamics of the cosmos.

Understanding this chapter is crucial for NEET aspirants because it includes conceptual questions, numerical applications, and observational astronomy, which are frequently tested in exams.

StudentBro notes provide exam-focused explanations, simple diagrams, and easy-to-understand concepts for effective learning.

Direct Links to Download 2025-26 Physics Notes (PDF)

► Click “Download Here” next to your subject to access the free PDF.

Celestial Bodies and Systems

• Stars: Luminous celestial bodies producing energy through nuclear fusion

  • Classified based on size, luminosity, and temperature

  • Examples: Sun, Betelgeuse, Sirius

• Planets and Satellites: Bodies orbiting stars or planets

• Galaxies: Massive systems of stars, dust, and gas

  • Types: Spiral, Elliptical, Irregular

• NEET may ask classification, examples, and basic properties of stars, planets, and galaxies.

Constellations and Cosmic Distance

• Constellations: Patterns of stars forming shapes; used for navigation and identification

• Light Year (ly): Distance traveled by light in one year (≈ 9.46 × 10¹² km)

• Parsec (pc): Distance at which 1 AU subtends 1 arcsecond (≈ 3.26 ly)

• Methods to Measure Distance: Parallax method, standard candles (Cepheid variables)

• NEET may ask conversion between light-years and parsecs, or distance calculations.

Hubble’s Law and Expansion of Universe

• Hubble’s Law: v = H₀ × d

  • v = recession velocity of galaxy

  • H₀ = Hubble constant

  • d = distance to galaxy

• Shows the universe is expanding

• Redshift: Light from distant galaxies shifts to longer wavelength due to expansion

• NEET may ask Hubble’s law formula, redshift, and significance of expansion.

Big Bang Theory

• Definition: Universe originated from a hot, dense singularity ~13.8 billion years ago

• Evidence for Big Bang:

  1. Cosmic Microwave Background Radiation (CMBR)

  2. Redshift of galaxies (Hubble’s observation)

  3. Abundance of light elements (H, He, Li)

• NEET may ask basic concept, evidence, and timeline of the Big Bang.

Life Cycle of Stars

• Protostar: Collapsing cloud of gas and dust

• Main Sequence Star: Stable star fusing hydrogen into helium

• Red Giant / Supergiant: Expansion when hydrogen is exhausted

• Final Stages:

  • Small stars → White Dwarf → Black Dwarf

  • Massive stars → Supernova → Neutron Star / Black Hole

• NEET questions often ask stages of stellar evolution and classification of stars.

Galaxies and Clusters

• Types of Galaxies:

  1. Spiral: Milky Way, Andromeda

  2. Elliptical: M87

  3. Irregular: LMC, SMC

• Galaxy Clusters: Groups of galaxies bound by gravity

• Superclusters: Clusters of galaxy clusters forming large-scale structure

• NEET may ask types of galaxies and examples.

Cosmological Concepts

• Observable Universe: Part of the universe accessible by light

• Dark Matter: Invisible mass influencing galaxy rotation

• Dark Energy: Causes accelerated expansion of universe

• Cosmic Horizon: Limit beyond which light cannot reach us

• NEET may ask definitions and significance of dark matter and dark energy.

Important Numerical and Formula Concepts

1. Hubble’s Law: v = H₀ × d

2. Redshift (z): z = Δλ/λ

3. Light year distance: 1 ly ≈ 9.46 × 10¹² km

4. Parsec: 1 pc ≈ 3.26 ly

5. Luminosity relation: L = 4πR²σT⁴

• Mastery of these formulas helps in solving conceptual and numerical NEET questions.

Tips for NEET Preparation on Universe

1. Memorize Hubble’s law, Big Bang theory, and cosmic distances

2. Understand life cycle of stars, types of galaxies, and cosmic expansion

3. Practice numerical problems involving distances, redshift, and luminosity

4. Learn observational astronomy concepts like parallax and standard candles

5. Relate concepts to real astronomical objects and phenomena

StudentBro notes include step-by-step explanations, diagrams, and solved examples for clarity and revision.

Advantages of StudentBro NEET Physics Notes

• Covers stars, galaxies, cosmic distances, Hubble’s law, Big Bang, and cosmological concepts

• Includes diagrams, examples, and real-world applications

• Structured for easy revision and conceptual clarity

• Focused on NEET syllabus and high-yield questions

These notes ensure aspirants can confidently tackle universe and cosmology questions in NEET exams.

Conclusion

The chapter Universe is a vital part of NEET Physics under modern physics and astronomy. Mastery of stars, galaxies, cosmic distances, Hubble’s law, and Big Bang theory is essential for solving conceptual and numerical problems.

StudentBro NEET Physics notes provide structured, clear, and exam-focused guidance, enabling aspirants to confidently solve universe-related questions and excel in NEET exams.