RRB NTPC Undergraduate CBT 1 16 Jun 2026 Shift 2 – Question Paper

Concept: Major multipurpose dams and their rivers.

1. Nagarjuna Sagar Dam is built across the Krishna river on the Telangana–Andhra Pradesh border (Nalgonda–Palnadu districts).
2. It is one of the world's largest masonry dams; its reservoir is also Krishna's.
3. Godavari has Sriram Sagar/Polavaram; Tungabhadra has the Tungabhadra Dam at Hospet.

Yaad rakhein: Krishna trio – Almatti, Srisailam, Nagarjuna Sagar.

Answer: (D) Krishna

Concept: Volume of a cylinder $V=\pi r^{2}h$. First find the radius of the second cylinder, then scale it by $\frac{3}{5}$.

1. Second cylinder: $\frac{22}{7}\times r^2\times 14=317900\Rightarrow 44r^2=317900\Rightarrow r^2=7225$, so $r=85$ cm.
2. Required radius $=\frac{3}{5}\times 85=51$ cm.
3. Volume $=\frac{22}{7}\times {51}^2\times 21=22\times 2601\times 3=171666$ cm${}^3$.

Trick: $h=21$ cancels the 7 neatly: $\frac{22}{7}\times 21=66$, so just compute $66\times 2601$.

Answer: (D) 171666 cm${}^3$

Concept: Check differences; if they are irregular, check the second differences.

1. Differences: $36-19=17,59-36=23,94-59=35,147-94=53$.
2. Second differences: $6,12,18$ → next $24$.
3. Next difference $=53+24=77$, so $?=147+77=224$.

Trick: When first differences grow unevenly, look for a pattern like $+6,+12,+18$ in the second level.

Answer: (B) 224