RRB NTPC Graduate CBT 1 16 Mar 2026 Shift 1 – Question Paper

Concept: Pascal's law: pressure applied to an enclosed fluid is transmitted equally and undiminished in all directions.

1. In a hydraulic lift/brake a small force on a small piston creates pressure that acts on a large piston, giving a large force ($F_2=F_1\times \frac{A_2}{A_1}$).
2. Faraday's law is about electromagnetic induction, Gay-Lussac's law about gas pressure–temperature, Coulomb's law about electric charges.

Yaad rakhein: Anything "hydraulic" (lift, brake, press, jack) → Pascal. Blood pressure instrument (sphygmomanometer) also uses it.

Answer: (C) Pascal's law

Concept: Heron's formula: Area $=\sqrt{s(s-a)(s-b)(s-c)}$ where $s=\frac{a+b+c}{2}$.

1. Sides $4:5:6$, perimeter $90$ → sides $=24,30,36$ cm and $s=45$.
2. Area $=\sqrt{45\times 21\times 15\times 9}=\sqrt{9^2\times 3^2\times 5^2\times 7}=135\sqrt{7}$.
3. With $\sqrt{7}=2.6$: area of $△PQR=135\times 2.6=351{\text{cm}}^2$.
4. Quadrilateral $=2\times 351=702{\text{cm}}^2$.

Trick: Break each factor into primes and pair them up before taking the root – $45·21·15·9$ gives $9·3·5$ outside and only $7$ left inside.

Answer: (B) $702{\text{cm}}^2$

Concept: Look at the differences between consecutive terms – here they form the prime numbers.

1. $89-87=2,87-84=3,84-79=5,79-72=7$.
2. Differences $2,3,5,7$ are consecutive primes, so the next difference is $11$.
3. $?=72-11=61$.

Trick: When differences are irregular (2, 3, 5, 7…), check primes first – it is the most common pattern in NTPC series.

Answer: (D) 61