Q&A: practice questions with answers

Concept: Article 21A was added by the 86th Amendment Act, 2002.

1. 21A: free and compulsory education for ages 6–14 as a Fundamental Right.
2. Same amendment changed Article 45 and added duty 51A(k).
3. The RTE Act came in 2009 (in force 2010).

Trick: '86 → 6 to 14' — the amendment number holds the age range digits.

Answer: (B) 86th Amendment Act

Concept: In a horizontal flow, faster fluid means lower pressure.

1. Continuity: A × v = constant → smaller area gives higher speed.
2. Bernoulli: P + ½ρv² = constant → higher v gives lower P.
3. So in the narrow part, speed ↑ and pressure ↓.

Trick: Speed and pressure always move in opposite directions — only (a) and (b) qualify; narrow pipe means faster.

Answer: (B) Speed increases, Pressure decreases

Concept: NSWS is a single digital window for investor approvals.

1. Launched in 2021 by the Ministry of Commerce & Industry.
2. Investors apply for central and state clearances/licences in one place.
3. Goal: ease of doing business.

Trick: 'Single Window' + Commerce Ministry → business clearances; other options belong to other ministries.

Answer: (B) Facilitate industrial approvals and clearances through a unified digital platform

Concept: Tippani is a work-based folk dance of the Saurashtra (Chorwad) region.

1. Women beat lime/clay floors with long poles called tippani — the rhythm became a dance (1 correct).
2. Men play dhol and nagara-type drums in support (2 correct).

Yaad rakhein: Other Gujarat folk dances: Garba, Dandiya Raas, Padhar, Bhavai (folk theatre).

Answer: (C) Both 1 and 2

Concept: Check A and R separately, then check the link.

1. A: India's HDI value has risen steadily since 2010 — true.
2. R: The Inequality-adjusted HDI (IHDI) was introduced in the 2010 report — true as a fact.
3. But IHDI is a separate index; India's progress came from health, education and income gains — R does not explain A.

Trick: A new measuring tool cannot cause real development — so the link fails.

Answer: (B) Both A and R are true, but R does not correctly explain A.

Concept: The Western Ghats are valued for monsoon influence and biodiversity.

1. They stop the south-west monsoon winds, giving heavy rain on the western slopes.
2. They are a global biodiversity hotspot with many endemic species.
3. Listed as a UNESCO World Heritage (natural) site in 2012.

Trick: Polar ecosystems near the equator and desert plants in rainforest hills are clearly absurd — eliminate.

Answer: (B) They play a vital role in shaping India's monsoon patterns and shelter immense biodiversity.

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

1. Condition: Rajya Sabha resolves by 2/3 of members present and voting that it is in the national interest.
2. Existing AIS: IAS, IPS, Indian Forest Service.
3. Rajya Sabha has this role because it represents the states.

Yaad rakhein: Article 249 is the other special Rajya Sabha power — Parliament can legislate on a State List subject by a similar 2/3 resolution.

Answer: (C) All India Services

Concept: Early Five-Year Plans had four goals: growth, modernisation, self-reliance, equity.

1. A: self-reliance was a key early goal — true.
2. R: newly independent India wanted to cut dependence on foreign aid and imports (even of food) — true.
3. R is exactly why self-reliance was chosen → R explains A.

Trick: When R states the purpose behind A, the answer is usually 'both true, R explains A'.

Answer: (A) Both A and R are true, and R is the correct explanation of A.

Concept: Interplanetary = travelling to another planet.

1. Mangalyaan (Mars Orbiter Mission) was launched 5 Nov 2013 by PSLV-C25.
2. It entered Mars orbit on 24 Sep 2014 — India was first to succeed on its first attempt.
3. Chandrayaan-1 → Moon (not a planet); Aditya-L1 → Sun–Earth L1 point; Gaganyaan → crewed LEO.

Trick: Moon and Sun are not planets — so only the Mars mission is interplanetary.

Answer: (D) Mangalyaan

Concept: Article 262 lets Parliament set up a special mechanism and keep courts out.

1. 262(1): Parliament may provide for adjudication of inter-state river disputes — 1 correct.
2. 262(2): Parliament may bar the Supreme Court; the Inter-State River Water Disputes Act, 1956 does so — 2 wrong.
3. Such disputes go to tribunals (e.g. Cauvery, Krishna).

Yaad rakhein: The River Boards Act, 1956 was passed the same year as the Disputes Act under the same constitutional scheme.

Answer: (A) Only 1

Concept: Solve brackets first, then × / ÷, then −.

1. First bracket: $5.125+2.8=7.925$
2. $0.45\times 7.925=3.56625$
3. Second bracket: $0.9÷0.3=3$
4. Result: $0.56625\approx 0.566$

Trick: $7.925\times 0.45$ is a bit above 3.5, minus 3 gives about 0.5–0.6 — only 0.566 fits.

Answer: (A) 0.566

Concept: Convert both percentages and collect P and Q terms.

1. 0.4(P + Q) = 0.6(P − Q) → 2(P + Q) = 3(P − Q)
2. 2P + 2Q = 3P − 3Q
3. P = 5Q → P : Q = 5 : 1

Trick: Divide the % by 20 first: 40 : 60 = 2 : 3, then solve 2(P+Q) = 3(P−Q).

Answer: (A) 5 : 1

Concept: Cost of mixture = weighted average of the two costs.

1. CP of 4 kg = $3\times 50+1\times 90=240$ → ₹60/kg
2. SP = ₹96/kg → profit = ₹36/kg
3. Profit % = $\frac{36}{60}\times 100=60\%$ gain

Trick: SP 96 is $1.6\times 60$, so gain = 60% directly.

Answer: (A) 60% Gain

Concept: Profit is shared in the ratio capital × time.

1. A → 8 months × ₹60,000; B → 9 months × ₹80,000
2. In thousands: 480 : 720 = 2 : 3
3. A gets 2 parts out of 5 → $40,000\times \frac{2}{5}=$ ₹16,000

Trick: Drop zeros: $(6\times 8):(8\times 9)=48:72=2:3$.

Answer: (A) ₹16,000

Concept: Removed value = old total − new total.

1. Old total = $40\times 70=2800$ kg
2. New total = $39\times 69.5=2710.5$ kg
3. Removed = $2800-2710.5=89.5$ kg

Trick: Removed = new avg + (old count × fall) = $69.5+40\times 0.5=89.5$.

Answer: (B) 89.5 kg

Concept: Change in average = error ÷ number of items.

1. Excess recorded = $154-145=9$ cm
2. Fall in average = $9÷30=0.3$ cm
3. Correct average is 149.7 cm (0.3 less than 150)

Trick: The true value is smaller, so the average must be below 150 — only 149.7 qualifies.

Answer: (A) 149.7 cm

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

1. $\frac{9680}{8000}=\frac{121}{100}$
2. $(1+\frac{R}{100}{)}^2=(\frac{11}{10}{)}^2$
3. $1+\frac{R}{100}=1.1\to R=10\%$

Trick: $121={11}^2$ is a sign of 10% for 2 years (100 → 110 → 121).

Answer: (A) 10%

Concept: If gain = CP of x units on selling n units, profit % = $\frac{x}{n}\times 100$.

1. Profit = CP of 5 kg; goods sold = 20 kg
2. Profit % = $\frac{5}{20}\times 100$
3. = 25%

Trick: Use the formula $\text{gain-goods}÷\text{sold-goods}\times 100$ — no need to use ₹900.

Answer: (B) 25%

Concept: Successive discounts multiply; order does not matter.

1. After 30% off: $15,000\times 0.7=$ ₹10,500
2. Other discount takes 10,500 to 9,000 → ₹1,500 off
3. Rate = $\frac{1500}{10500}\times 100=\frac{1}{7}\times 100\approx 14.28\%$

Trick: $\frac{9000}{15000}=\frac{3}{5}=0.7\times (\frac{6}{7})$ → other discount = $\frac{1}{7}=14.28\%$.

Answer: (C) 14.28%

Concept: The unchanged component (alcohol) fixes the unit size.

1. Alcohol stays 5 units: 5 : 3 → 5 : 9
2. Water increases 9 − 3 = 6 units = 24 L → 1 unit = 4 L
3. Initial mixture = 8 units = 32 L

Trick: Make the constant part equal in both ratios, then compare the changed part.

Answer: (A) 32 litres