PYQPulse
HomeMocksPracticePYQsUpdatesDashboard
PYQPulse

Timing-accurate mock tests and PYQs for SSC, Banking and Railway exams — so the real paper feels like a revision.

Exams

  • SSC exams
  • Banking exams
  • Railway exams
  • All exams

Practice

  • Practice questions
  • Mock test series
  • Sectional tests
  • Year-wise PYQs
  • Performance analytics

Company

  • About us
  • Help Centre
  • Pricing
  • Sign in

Legal

  • Privacy Policy
  • Terms of Service

Contact

  • hello@testwala.co.in
  • Telegram
  • +91 62816 87760

Practice interface modeled on the official exam pattern — not the official examination. PYQPulse is not affiliated with the Staff Selection Commission, IBPS, SBI, RBI, NABARD, SEBI or Indian Railways.

© 2026 PYQPulse. All rights reserved.

Built for aspirants, by aspirants.

HomeMocksPracticeStats
  1. Home
  2. ›
  3. PYQs
  4. ›
  5. UPPSC PCS
  6. ›
  7. 2018
  8. ›
  9. Q28

UPPSC PCS 2018 · Question 28 of 142

Ultra-violet radiation from sunlight causes the reaction that produces which of the following?

Environment

  1. ACO
  2. BSO2
  3. CO3Correct
  4. DFluorides

Answer: C. O3

Explanation

UV radiation splits oxygen molecules, leading to formation of ozone (O3) in the stratosphere.

Source: https://www.onlyiasexam.com/2021/10/2018-uppsc-pre-solved-question-papers.html

← Q27View full paper (142 questions)Q29 →

Practice the full UPPSC PCS 2018 paper

Timed test with all 142 questions, just like the real exam.

Start test