UPSC Prelims 2026 · GS Paper I
Question 86: Science and Technology
Which of the following statements regarding the features of blockchain technology are correct ?
- 1.Records stored in the database may be made visible to relevant stakeholders without risk of alteration.
- 2.Copies of the entire database are stored on multiple computers on a network, syncing within seconds.
- 3.Consortium blockchain is a blend of public and private blockchains allowing selective data access.
- 4.Mathematical algorithms make it impossible to change or delete any data once recorded and accepted.
Select the answer using the code given below :
AnswerUPSC’s answer is (c).
Blockchain keeps records in a database that stakeholders can view without risk of alteration (1), stores copies of the entire database on many computers that sync within seconds (2), and uses mathematical algorithms to make it effectively impossible to change or delete data once recorded and accepted (4). A hybrid blockchain, rather than a consortium blockchain, is the blend of public and private blockchains; a consortium blockchain is run by a group of organisations, so statement 3 is not accepted.
- 1. Records can be viewed by stakeholders without risk of alteration.
- 2. Copies of the database are held on multiple computers and sync within seconds.
- 3. The blend of public and private is a hybrid blockchain; a consortium is run by a group of organisations.
- 4. Algorithms make recorded and accepted data practically unchangeable.
How you could have got this
- If you were sure statement 1 is correct, (b) goes: it leaves 1 out.
What you needed to know: Records can be viewed by stakeholders without risk of alteration.
- Then, if you were sure statement 2 is correct, (a) and (d) go: each of them leaves 2 out.
What you needed to know: Copies of the database are held on multiple computers and sync within seconds.
Only (c) is left. You didn’t need statements 3 or 4.
This follows UPSC’s provisional key; the final key could change it.
Which options go is worked out from UPSC’s key and the options, not by a model.
Why each option is right or wrong
- (a) Wrong: statement 3 is not accepted, and it omits statements 2 and 4.
- (b) Incomplete: statement 1 is also correct.
- (c) Right: statements 1, 2 and 4 are correct.
- (d) Incomplete: statement 2 is also correct.
Only the provisional key (27 May 2026) was found; the final key replaces it when found.
Answer: UPSC’s key. Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 2026, General Studies Paper I, Series A. The paper on upsc.gov.in.