RRB ALP CBT 1 2025 PYQs

Concept: Cilia lining the upper respiratory tract (nose, trachea, bronchi) sweep dust and germs out; smoke destroys them.

1. Hair-like cilia in the upper respiratory tract push mucus with trapped dust and germs out of the airway.
2. Tobacco smoke damages and destroys these cilia, so dust, smoke particles and germs enter the lungs.
3. Result: chronic cough, infections, bronchitis and higher risk of lung cancer.

Short trick: Smoke = 'sweepers' (cilia) killed at the entrance (upper tract) – the gatekeepers fall first.

Answer: (B) Destruction of cilia in upper respiratory tract

Concept: For an object between C and F of a concave mirror, the image forms beyond C.

1. Ray parallel to the axis reflects through F; ray through F reflects parallel to the axis.
2. The reflected rays actually meet beyond C, below the axis → image is real and inverted.
3. The image distance is more than the object distance → image is enlarged.

Short trick: Object and image swap: object beyond C ↔ image between F and C. So object between C and F → image beyond C, enlarged, real, inverted.

Answer: (D) Enlarged, real, and inverted

Concept: Average speed = total distance ÷ total time; in uniform acceleration from rest it equals (u + v)/2.

1. Distance in 2 s: $s=\frac{1}{2}g{t}^2=\frac{1}{2}\times 10\times 2^2=20$ m.
2. Average speed = 20 ÷ 2 = 10 m/s.
3. Check: v = gt = 20 m/s; (0 + 20)/2 = 10 m/s ✓.

Short trick: From rest, average speed = $\frac{gt}{2}$ = 10 × 2 ÷ 2 = 10 m/s.

Answer: (B) 10 m/s

Concept: In a hypertonic solution a plant cell loses water by osmosis – this is plasmolysis.

1. Water moves out of the vacuole and cytoplasm to the more concentrated outside solution.
2. The protoplast shrinks, but the rigid cell wall keeps its shape.
3. So the cell contents contract and pull away from the cell wall.

Short trick: Plasmo-LYSIS = protoplasm 'lets go' of the wall; swelling and bursting happens only to animal cells (no wall) in water.

Answer: (D) They contract and move away from the cell wall

Concept: Gravitational PE near the earth: $E_p=mgh$.

1. m = mass of the object, h = height above the reference level, g = constant (≈ 9.8 m/s²).
2. PE does not depend on velocity, speed or acceleration of the object (those affect kinetic energy, $\frac{1}{2}m{v}^2$).
3. So it depends on mass and height.

Short trick: Potential = Position: 'P for Position' → height; Kinetic = Kinetic motion → speed.

Answer: (D) Its mass and height

Concept: Shape of epithelial cells matches their job.

1. Cuboidal epithelium – cube-shaped cells that absorb/secrete: lining of kidney tubules (and salivary-gland ducts) → I-C.
2. Columnar epithelium – tall cells for absorption: lining of the intestine → II-A.
3. Squamous epithelium – flat, thin cells; stratified squamous forms the skin → III-B.

Short trick: C-K-C: Cuboidal = Kidney; Columnar = Canal (intestine); Squamous = Skin (both start with S).

Answer: (C) I-C; II-A; III-B

Concept: Excess HCl in the stomach is neutralised by a mild base (antacid).

1. Milk of magnesia, Mg(OH)₂, is a mild base.
2. Mg(OH)₂ + 2HCl → MgCl₂ + 2H₂O (neutralisation).
3. Lemon juice, HCl and vinegar are acids – they would increase acidity.

Short trick: Acid trouble → take a base: 'Milk of Magnesia' = Mg(OH)₂. Eliminate all sour options.

Answer: (B) Antacids like Mg(OH)₂

Concept: Matter is made of tiny particles with spaces between them.

1. When sugar dissolves, its particles spread into the spaces between water particles.
2. Hence the water level does not rise noticeably – evidence of small particles and inter-particle spaces.
3. Oil floating, chalk staying visible and sand settling show insolubility/density, not particle nature.

Short trick: 'Disappears but level stays' = particles hide in the gaps – the classic NCERT Class 9 activity.

Answer: (C) Sugar dissolves in water without change in level.

Concept: Exercise Cyclone is the joint special-forces exercise of India and Egypt.

1. The 3rd edition, Exercise Cyclone 2025, was held from 10 to 23 February 2025.
2. Venue: Mahajan Field Firing Range, Rajasthan (desert and semi-desert terrain).
3. Focus: special-forces skills, counter-terror operations and interoperability.

Short trick: Cyclone from Egypt's desert to India's desert – Mahajan (Bikaner region), the same range used for many joint drills.

Answer: (B) Mahajan Field Firing Range, Rajasthan

Concept: The Public Accounts Committee (PAC) has 22 members.

1. 15 members are elected from Lok Sabha and 7 from Rajya Sabha (by proportional representation, single transferable vote).
2. Term: one year; the Chairman is appointed by the Lok Sabha Speaker (by convention from the opposition).
3. PAC examines the audit reports of the CAG on government spending.

Short trick: PAC = 15 + 7 = 22 (Estimates Committee = 30, all from Lok Sabha).

Answer: (B) 7

Concept: SP = MP × (1 − d%) and SP = CP × (1 + profit%).

1. Let CP = 100 → MP = 140, SP = 110.
2. Discount = 140 − 110 = 30.
3. $d=\frac{30}{140}\times 100=\frac{150}{7}=21\frac{3}{7}\mathrm{\%}$

Short trick: $d\mathrm{\%}=\frac{\text{Markup}-\text{Profit}}{100+\text{Markup}}\times 100=\frac{40-10}{140}\times 100$

Answer: (C) $21\frac{3}{7}\mathrm{\%}$

Concept: Required SP = CP × (1 + gain%); discount is taken on MP.

1. Let CP = 100 → MP = 120.
2. Required SP = 102.
3. Discount = 120 − 102 = 18 → $\frac{18}{120}\times 100=15\mathrm{\%}$

Short trick: $\frac{20-2}{120}\times 100=15\mathrm{\%}$

Answer: (B) 15%

Concept: Interest of the 2nd year = interest of the 1st year + interest on that interest = $P\cdot r(1+r)$.

1. 1st-year interest $=\frac{3072}{1.2}=2560$
2. $P=\frac{2560}{0.20}=12800$

Short trick: $P=\frac{3072}{0.2\times 1.2}=\frac{3072}{0.24}=12800$

Answer: (B) ₹12800

Concept: $SI=\frac{P\times R\times T}{100}$

1. $480=\frac{P\times 10\times 2}{100}=\frac{P}{5}$
2. $P=480\times 5=2400$

Short trick: Total rate = 10% × 2 = 20% → 20% of P = 480 → P = 480 × 5 = 2400.

Answer: (D) 2400

Concept: Overall profit % = weighted average of the individual profit % (weights = share of goods).

1. Shares: 50%, 32% of remaining 50% = 16%, rest = 34%.
2. Overall = 0.50 × 49 + 0.16 × 45 − 0.34 × 15
3. = 24.5 + 7.2 − 5.1 = 26.6%

Short trick: Take 100 units of cost 1 each: profit = 24.5 + 7.2 − 5.1 = 26.6 on 100 → 26.6%.

Answer: (B) 26.6%

Concept: Make equal decimal places, find LCM of the whole numbers, then put back the decimal.

1. 1.30, 7.60, 0.13 → 130, 760, 13 (÷100 later).
2. $130=2\times 5\times 13$, $760=2^3\times 5\times 19$, $13=13$
3. LCM $=2^3\times 5\times 13\times 19=9880$ → 98.8

Short trick: LCM must be divisible by 7.6 and 1.3: 98.8 ÷ 7.6 = 13 and 98.8 ÷ 1.3 = 76 – only 98.8 works.

Answer: (B) 98.8

Concept: Mode = the value that occurs most often.

1. 44 appears 3 times (positions 1, 16, 18).
2. 40, 42, 46, 51, 55 appear twice each; others once.
3. Mode = 44

Short trick: Scan only the options: 44 → 3 times, 51, 55, 40 → 2 times each.

Answer: (A) 44

Concept: Form the equation and reverse the operations.

1. $\frac{n}{3}+25=87\Rightarrow \frac{n}{3}=62$
2. $n=186$
3. Digit sum = 1 + 8 + 6 = 15

Short trick: Work backwards: (87 − 25) × 3 = 186.

Answer: (B) 15

Concept: Volume of water stays the same: $\frac{1}{3}\pi R^{2}H=\pi r^{2}h$.

1. $r=\frac{R}{3}$
2. $\frac{1}{3}\pi R^2(19)=\pi \frac{R^2}{9}h$
3. $h=\frac{19\times 9}{3}=57$ cm

Short trick: $h=\frac{H}{3}\times {\left(\frac{R}{r}\right)}^2=\frac{19}{3}\times 9=57$

Answer: (C) 57 cm

Concept: Area = ½ × base × height; with the same base, area ∝ height.

1. First triangle: $98=\frac{1}{2}\times 14\times h_1\Rightarrow h_1=14$ cm
2. Second area = 196 → $h_2=\frac{2\times 196}{14}=28$ cm

Short trick: Same base, area doubled → height doubled: 14 × 2 = 28 cm.

Answer: (B) 28 cm