Daily Challenge
Saturday, 17 October 2026
Daily Challenge — 17 October 2026
Three UPSC Prelims-pattern questions — one each from the GS I, GS II and GS III subject areas. Attempt all three before checking your answers.
The Universe and the Earth
A ship sailing eastward from Japan towards Hawaii crosses the International Date Line on a Tuesday. Immediately after crossing the line, the date on board will be
Correct answer: D
Crossing the International Date Line eastward (from the Asian side to the American side) sets the date back by one day, so Tuesday becomes Monday. Crossing westward would advance it to Wednesday, which is the trap in option A. The date always changes on crossing the line, so option B is wrong.Fundamental Rights
Which of the following Fundamental Rights are available only to citizens of India?
- Article 14
- Article 16
- Article 19
- Article 21
Correct answer: B
Articles 15, 16, 19, 29 and 30 are available only to citizens. Articles 14 and 21 use the word person and also protect non-citizens, so only Articles 16 and 19 qualify.Space Technology
Which one of the following statements about cryogenic rocket engines is correct?
Correct answer: A
A cryogenic engine burns liquid hydrogen with liquid oxygen, both stored at very low temperatures. Kerosene with liquid oxygen is a semi-cryogenic combination. PSLV has no cryogenic stage; its first stage is solid. Cryogenic engines have the highest efficiency, which is exactly why they are used in upper stages of GSLV and LVM3.