UPSC & BPSC Science and Technology MCQs 2025: Previous Year + Current Affairs Questions

Introduction

As we know, Science and Technology is one of the most important topics for both UPSC and BPSC Prelims Exam. Every year, 8–10 questions are directly asked from this section.
In this post, we will cover 20 most important Science and Technology MCQs for UPSC & BPSC 2025, including previous year questions with year mentioned and current affairs based questions.
All questions are given with answers and explanations in easy language, so that students can easily understand and revise before exam.

1. (BPSC Prelims 2023 – 69th BPSC)

Question: Which of the following technologies will be enabled by the 5G mobile communication networks?

1. Internet of Things
2. Edge Computing
3. Network Slicing
   Options:
   A. 1 and 2 only
   B. 2 and 3 only
   C. 1 and 3 only
   D. 1, 2 and 3
   Answer: D
   Explanation: All three are correct. 5G supports IoT devices, allows edge computing, and provides network slicing for multiple virtual networks.

2. (BPSC Prelims 2022)

Question: Which among the following are constituents of brass?
A. Iron and zinc
B. Copper and nickel
C. Iron and copper
D. Zinc and copper
Answer: D
Explanation: Brass is an alloy made of copper and zinc. It is used in making utensils and musical instruments.

3. (BPSC Science Question Bank 2021)

Question: Which of the following carries a negative charge?
A. X-rays
B. Alpha particles
C. Beta particles
D. Gamma rays
Answer: C
Explanation: Beta particles are electrons, and electrons have a negative charge.

4. (BPSC Prelims 2020)

Question: The speed of light will be minimum while passing through —
A. Vacuum
B. Air
C. Glass
D. Water
Answer: C
Explanation: Light travels fastest in vacuum and slowest in denser mediums like glass.

5. (BPSC Prelims 2020)

Question: Common salt is —
A. Sodium carbonate
B. Sodium chloride
C. Calcium oxide
D. Calcium chloride
Answer: B
Explanation: Common salt is Sodium Chloride (NaCl), which we use in daily cooking.

6. (BPSC Prelims 2019)

Question: Damaged CFL and fluorescent tubes must be disposed safely as they contain ______ vapours that are toxic in nature.
A. Ammonium
B. Sulphur dioxide
C. Nitrogen dioxide
D. Mercury
Answer: D
Explanation: CFL bulbs contain mercury vapour, which is harmful to health and environment.

7. (UPSC Prelims 2021)

Question: With reference to ‘Software as a Service (SaaS)’, consider the following statements:

1. SaaS buyers can customise the interface
2. SaaS users can access data through mobile devices
3. Outlook, Hotmail and Gmail are forms of SaaS
   Answer: 2 and 3 only
   Explanation: SaaS allows access to software via the internet, like Gmail or Google Drive.

8. (UPSC Prelims 2020)

Question: In the context of space technology, what is ‘Bhuvan’, recently in news?
A. A mini satellite launched by ISRO
B. A moon impact probe
C. A geoportal of ISRO with 3D imaging
D. A space telescope developed by India
Answer: C
Explanation: Bhuvan is an ISRO geoportal that provides 3D visualization of Indian locations.

9. (UPSC Prelims 2019)

Question: Rainbow is produced when sunlight falls on drops of rain. Which physical phenomena are responsible?

1. Dispersion
2. Refraction
3. Internal Reflection
   Answer: 1, 2, and 3
   Explanation: Rainbow forms due to dispersion, refraction, and internal reflection of sunlight inside raindrops.

10. (UPSC Prelims 2018)

Question: A new optical disc format known as Blu-ray Disc (BD) is different from DVD because —

1. BD supports HD video while DVD supports SD video.
2. BD has more storage capacity than DVD.
   Answer: 1 and 2
   Explanation: Blu-ray uses blue laser and can store about 25GB data, while DVD stores around 4.7GB.

Current Affairs Based Science & Tech Questions (2024–2025)

11. (Current Affairs 2025)

Question: LUPEX (Lunar Polar Exploration) is a joint mission of which two space agencies?
A. NASA and ISRO
B. ISRO and JAXA
C. ESA and NASA
D. CNSA and ISRO
Answer: B
Explanation: LUPEX is a joint moon mission between ISRO (India) and JAXA (Japan).

12. (Current Affairs 2025)

Question: India’s first human space mission “Gaganyaan” is planned to be launched in —
A. 2022
B. 2023
C. 2024
D. 2025
Answer: C
Explanation: As per ISRO, Gaganyaan is expected around 2024–25 with Indian astronauts on board.

13. (Current Affairs 2024)

Question: Which institute has developed a 3D hydrogel system to study Tuberculosis?
A. IIT Delhi
B. AIIMS
C. IISc Bangalore
D. NIRT Chennai
Answer: C
Explanation: IISc Bengaluru developed a hydrogel system to study TB infection under lab conditions.

14. (Current Affairs 2024)

Question: Which country developed the first deep-UV laser device?
A. USA
B. China
C. Japan
D. Germany
Answer: B
Explanation: China recently developed the world’s first deep-ultraviolet laser device for chip research.

15. (Current Affairs 2024)

Question: India became the 6th country to have its own deep-sea mission program in —
A. 2020
B. 2021
C. 2022
D. 2023
Answer: D
Explanation: The Deep Ocean Mission was launched to explore minerals and biodiversity under the sea.

16. (Current Affairs 2022)

Question: 5G telecommunication technology was commercially launched in India in —
A. 2019
B. 2020
C. 2022
D. 2023
Answer: C
Explanation: 5G officially launched in India on 1 October 2022 by Prime Minister Narendra Modi.

17. (Current Affairs 2023)

Question: “Supersolid” mentioned in recent science news is related to —
A. Quantum Mechanics
B. Thermodynamics
C. Magnetism
D. Biotechnology
Answer: A
Explanation: Supersolid is a new state of matter showing both superfluid and solid properties.

18. (Current Affairs 2023)

Question: India’s first intranasal COVID vaccine was developed by —
A. Cadila
B. Bharat Biotech
C. Cipla
D. Serum Institute
Answer: B
Explanation: Bharat Biotech launched “iNCOVACC”, India’s first intranasal COVID vaccine.

19. (Current Affairs 2024)

Question: Which of the following are correct about 5G networks?

1. Supports edge computing
2. Allows network slicing
3. Enables IoT
   Answer: All (1, 2, 3)
   Explanation: 5G technology combines all three features for faster, reliable, and smart connectivity.

20. (Current Affairs 2025)

Question: Which lab was recently certified to test 5G core network functions in India?
A. DRDO Lab
B. IIT Madras TSTL
C. ISRO Space Division
D. BARC Mumbai
Answer: B
Explanation: IIT Madras’s Telecom Security Testing Lab became India’s certified 5G testing centre.