Q&A: practice questions with answers

Concept: The amendment with the widest changes is called the Mini-Constitution.

1. 42nd Amendment, 1976 (Emergency period, Swaran Singh Committee).
2. Added 'Socialist, Secular, Integrity' to the Preamble and Fundamental Duties (Art. 51A).
3. 44th Amendment (1978) later undid several of its changes.

Yaad rakhein: 42 = 'Mini-Constitution'; 44 = 'Right to Property removed from FRs'.

Answer: (D) 42nd Amendment Act, 1976

Concept: Steam at 100°C holds extra energy (latent heat of vaporisation).

1. Latent heat of vaporisation of water ≈ 2260 J/g (≈ 540 cal/g).
2. When steam touches skin it condenses and gives out this heat first, then cools like hot water.
3. Temperature is the same; the extra hidden heat causes deeper burns.

Yaad rakhein: Same idea: ice at 0°C cools better than water at 0°C (latent heat of fusion ≈ 80 cal/g).

Answer: (B) Because steam releases additional latent heat upon condensation.

Concept: eSanjeevani is the Health Ministry's national telemedicine service with two variants.

1. eSanjeevani OPD: patient-to-doctor video consultation from home ✓.
2. eSanjeevani AB-HWC: doctor-to-doctor link from Ayushman Arogya Mandirs (HWCs) to specialists at hubs ✓.

Yaad rakhein: eSanjeevani was developed by C-DAC Mohali.

Answer: (C) Both 1 and 2

Concept: Group folk dance of Kumaon, Uttarakhand.

1. Men and women dance in a circle, arms linked, at spring fairs ✓.
2. Hurka (small hourglass drum) is the main accompanying instrument ✓.

Yaad rakhein: Other Kumaoni dances: Chhapeli, Chholiya (sword dance).

Answer: (B) Both 1 and 2

Concept: The World Bank's Doing Business study covered formal firms only.

1. It assessed regulations faced by registered businesses in the largest business city → informal sector excluded (A true).
2. Informal units have no uniform records, so cross-country comparison is impossible (R true).
3. This data problem is the reason for exclusion → R explains A.

Yaad rakhein: The Doing Business report was discontinued by the World Bank in 2021; the new framework is B-READY.

Answer: (A) Both A and R are true, and R correctly explains A.

Concept: Railways aims to be a net-zero carbon emitter by 2030.

1. Electrifying the broad-gauge network replaces diesel engines.
2. Solar and wind power are being added for traction and stations.
3. Other options increase emissions or are absurd.

Trick: Eliminate options that would raise pollution (coal, road freight) — answer is obvious.

Answer: (C) Electrifying broad-gauge routes and adopting renewable energy sources

Concept: P.C. Mahalanobis designed the strategy of the Second Five-Year Plan (1956–61).

1. It gave top priority to heavy industry and capital goods (A true).
2. Goal: a self-reliant industrial base that would sustain long-run growth (R true).
3. The goal explains the focus → R explains A.

Yaad rakhein: Second Plan = 'Mahalanobis Plan'; steel plants at Bhilai, Durgapur, Rourkela came up in this period.

Answer: (A) Both A and R are true, and R correctly explains A.

Concept: Part XVII (Art. 343–351) deals with official language.

1. Art. 343: Hindi in Devanagari script is the official language of the Union.
2. Art. 344: Official Language Commission; Art. 348: language of courts/laws; Art. 351: development of Hindi.

Yaad rakhein: Part XVII starts at 343 — the very first article names Hindi.

Answer: (B) Article 343

Concept: Landform depends on how plates move: apart, together, or sideways.

1. Mid-ocean ridge – plates move apart → divergent.
2. Mariana Trench – Pacific plate sinks under another → convergent.
3. San Andreas Fault – plates slide past → transform.

Trick: Ridge = apart, Trench = together, Fault (San Andreas) = sideways.

Answer: (B) 1-Divergent, 2-Convergent, 3-Transform

Concept: Art. 312 lets Parliament create new All India Services.

1. Rajya Sabha must first pass a resolution by 2/3 of members present and voting, in national interest → Statement 1 correct.
2. Art. 312 names no 'Security Services' → Statement 2 wrong.

Yaad rakhein: Existing AIS: IAS, IPS and Indian Forest Service (IFoS, added 1966).

Answer: (A) Only 1

Concept: $\frac{P}{S}=(\frac{P}{Q})\times (\frac{Q}{R})\times (\frac{R}{S})$.

1. $\frac{P}{S}=\frac{7}{5}\times \frac{2}{3}\times \frac{4}{5}$.
2. Numerator $7\times 2\times 4=56$; denominator $5\times 3\times 5=75$.
3. P : S = 56 : 75.

Trick: Multiply all antecedents and all consequents directly — no need to make Q and R equal.

Answer: (B) 56 : 75

Concept: Division by a fraction = multiplication by its reciprocal. (Expression: $(\frac{8}{5}÷\frac{14}{5})\times (\frac{10}{7}÷\frac{4}{3})$.)

1. $\frac{8}{5}÷\frac{14}{5}=\frac{8}{14}=\frac{4}{7}$.
2. $\frac{10}{7}÷\frac{4}{3}=\frac{10}{7}\times \frac{3}{4}=\frac{30}{28}=\frac{15}{14}$.
3. $\frac{4}{7}\times \frac{15}{14}=\frac{60}{98}=\frac{30}{49}=\frac{120}{196}$.

Trick: Reduce every option: $\frac{120}{196}=\frac{30}{49}$ — matches; $\frac{180}{196}=\frac{45}{49}$ does not.

Answer: (A) $\frac{120}{196}$

Concept: Convert fractions to decimals, then solve brackets. (Expression: $(3.5+\frac{3}{8})-(\frac{9}{5}\times 1.25)$.)

1. $\frac{3}{8}=0.375\to 3.5+0.375=3.875$.
2. $\frac{9}{5}=1.8\to 1.8\times 1.25=2.25$.
3. $3.875-2.25=1.625$.

Trick: $1.25=\frac{5}{4}$, so $\frac{9}{5}\times \frac{5}{4}=\frac{9}{4}=2.25$ instantly.

Answer: (B) 1.625

Concept: Use exact fractions, divide, then add. (Expression: $((1.5+\frac{1}{6})÷(2.25-\frac{1}{3}))+0.8$.)

1. $1.5+\frac{1}{6}=\frac{3}{2}+\frac{1}{6}=\frac{10}{6}=\frac{5}{3}$.
2. $2.25-\frac{1}{3}=\frac{9}{4}-\frac{1}{3}=\frac{23}{12}$.
3. $\frac{5}{3}÷\frac{23}{12}=\frac{5}{3}\times \frac{12}{23}=\frac{20}{23}\approx 0.87$.
4. $0.87+0.8\approx 1.67$ → nearest option 1.66.

Trick: The bracket value is just under 1, so the answer is just under 1.8 — only 1.66 fits.

Answer: (D) 1.66

Concept: Use the two liquids with known additions to find the multiplier.

1. Initially $P=4k,Q=6k,R=10k$.
2. $\frac{4k+6}{6k+12}=\frac{6}{10}\to 40k+60=36k+72\to k=3$.
3. New P is 18 L for 6 parts, so each part is 3 L; R finally has 16 parts = 48 L.
4. R at the start was $10\times 3=30$ L, hence 18 L was poured in.

Trick: Cross-check Q: $18+12=30$ = 10 parts × 3 ✓ — confirms 1 part = 3 L.

Answer: (B) 18 liters

Concept: Profit share ∝ capital × time.

1. Ashish: ₹60,000 × 24 months.
2. Sachin: ₹35,000 × 16 months (joined after 8).
3. Ratio = $60\times 24:35\times 16=1440:560=18:7$.

Trick: Cancel first: 60 : 35 = 12 : 7 and 24 : 16 = 3 : 2 → 36 : 14 = 18 : 7.

Answer: (D) 18 : 7

Concept: Weight of leaver = old total − new total.

1. Old total = $13\times 65=845$ kg.
2. New total = $12\times 65.5=786$ kg.
3. Leaver = $845-786=59$ kg.

Trick: Average rose by 0.5 for 12 people → leaver = $65-12\times 0.5=59$.

Answer: (A) 59

Concept: Average = sum of Q's values ÷ number of days (sales in ₹ thousand).

1. Q's sales: 75, 64, 62, 68.
2. Sum = 269.
3. Average = $269÷4=67.25$.

Trick: Take 65 as base: deviations $+10,-1,-3,+3=+9$ → $65+\frac{9}{4}=67.25$.

Answer: (B) ₹67.25

Concept: $A=P(1+\frac{R}{100}{)}^n$.

1. Year 1 interest: 10% of 50,000 = 5,000 → 55,000.
2. Year 2: 10% of 55,000 = 5,500 → 60,500.
3. Year 3: 6,050 more → ₹66,550.

Trick: 10% CI for 3 years = 33.1% effective → 50,000 + 16,550.

Answer: (C) ₹66,550

Concept: SP = CP + Profit.

1. Profit = 3 parts, CP = 8 parts.
2. SP = 11 parts.
3. SP : Profit = 11 : 3.

Trick: Add the two terms of the given ratio to get SP.

Answer: (D) 11 : 3