Q&A: practice questions with answers

Concept: Several jurists have described the DPSP (Part IV) in memorable phrases that are frequently asked.

1. L. M. Singhvi called the Directive Principles the 'life-giving provisions of the Constitution'.
2. Other quotes: Granville Austin – 'conscience of the Constitution'; B. R. Ambedkar – 'novel features'; K. T. Shah – 'cheque payable at the convenience of the bank'; Nasiruddin – 'new year's resolutions'.
3. DPSP are not legal rights – they are non-justiciable (Article 37).

Yaad rakhein: Singhvi = life-giving; Austin = conscience; K.T. Shah = cheque; Nasiruddin = new-year resolutions.

Answer: (C) Life-giving provisions of the Constitution

Concept: Articles 124–147 deal with the Union Judiciary; each power of the Supreme Court has its own article.

1. Article 137 – power of the Supreme Court to review any judgment or order made by it (review petition, and the basis of curative petitions).
2. Article 136 – special leave to appeal (SLP); Article 141 – law declared by SC binding on all courts; Article 145 – rules of the Court.

Yaad rakhein: 136 SLP → 137 Review → 141 Binding law → 142 Complete justice → 143 Advisory.

Answer: (A) Article 137

Concept: Refraction is the bending of light when it passes obliquely from one transparent medium to another because its speed changes.

1. Example: a pencil looks bent in water, a pool looks shallower – light goes air → water (two media).
2. Reflection is bouncing back in the same medium; scattering is spreading by particles; diffraction is bending around edges/slits.

Yaad rakhein: 'One medium to another' = Refraction (Snell's law, $\mu =\frac{\sin i}{\sin r}$).

Answer: (A) refraction

Concept: The 97th Constitutional Amendment Act, 2011 dealt with cooperative societies.

1. It made 'forming cooperative societies' a fundamental right under Article 19(1)(c), added Article 43B (DPSP) and inserted Part IX-B (Articles 243ZH–243ZT).
2. District Planning Committees and Metropolitan Planning Committees came through the 74th Amendment (1992).

Yaad rakhein: 73rd Panchayat (IX), 74th Municipality (IX-A), 97th Cooperatives (IX-B).

Answer: (D) Cooperative Societies

Concept: Mechanical energy is the energy an object has because of its motion or position.

1. Total mechanical energy = kinetic energy ($\frac{1}{2}m{v}^2$, due to motion) + potential energy ($mgh$, due to position/configuration).
2. In the absence of friction this sum stays constant – e.g. a falling body loses PE and gains the same KE.
3. Heat, sound, light, chemical and electrical energies are non-mechanical forms.

Yaad rakhein: ME = KE + PE; conservation of mechanical energy is the pendulum/roller-coaster principle.

Answer: (A) Potential and kinetic energy

Concept: System software (operating system, utilities) manages hardware and resources; application software does user tasks.

1. Allocating memory to programs is a core operating-system function (memory management) – handled by system software.
2. Designing a presentation, editing a photo or playing a video is done by application programs (PowerPoint, Photoshop, VLC).

Yaad rakhein: OS jobs: process, memory, file and device management. Anything the 'user clicks to create' is an application.

Answer: (B) Allocating memory to programs

Concept: IIT Bhubaneswar (established 2008) is organised into 'Schools' rather than departments.

1. The School of Minerals, Metallurgical and Materials Engineering (SMMME) was set up in 2012, reflecting Odisha's mineral-rich base.
2. It is a distinct school; the older schools include Basic Sciences, Electrical Sciences, Mechanical Sciences and Infrastructure.

Yaad rakhein: IIT Bhubaneswar 2008 → SMMME 2012 (four years later).

Answer: (B) 2012

Concept: The Earth has three main layers – crust, mantle and core – separated by seismic discontinuities.

1. The mantle–core boundary (Gutenberg discontinuity) lies at a depth of about 2,900 km.
2. Crust–mantle boundary (Mohorovičić) is at ~35 km under continents; the outer–inner core boundary (Lehmann) at ~5,150 km; the centre is at ~6,371 km.

Yaad rakhein: Moho 35 → Gutenberg 2900 → Lehmann 5150 → centre 6371 km.

Answer: (A) 2,900 km

Concept: An absolute path in Windows starts from the drive letter and goes down to the file; the root of a drive is written as the drive letter followed by a backslash.

1. Root of the main drive = C:\, so the file is C:\config.ini.
2. config.ini and \config.ini are relative/incomplete (they depend on the current drive/folder); C:\Users\config.ini puts the file inside the Users folder, not the root.

Yaad rakhein: Absolute = drive letter + full folder chain + file name; Windows uses backslash, Linux uses forward slash from '/'.

Answer: (D) C:\config.ini

Concept: The 1990–91 balance of payments crisis forced India into the 1991 economic reforms (LPG).

1. By mid-1991 forex reserves had fallen to roughly 1 billion dollars – enough to pay for only about two weeks of imports.
2. India pledged gold to the Bank of England and took an IMF loan; the New Economic Policy followed under PM Narasimha Rao and FM Manmohan Singh.

Yaad rakhein: 1991: reserves for 2 weeks, gold pledged, rupee devalued, LPG reforms.

Answer: (A) two weeks

Concept: The Civil Disobedience Movement began with the Salt Satyagraha.

1. Gandhi marched from Sabarmati Ashram to Dandi (12 March – 5 April 1930, 240 miles) and broke the Salt Law on 6 April 1930.
2. 1929 was the Lahore session (Purna Swaraj); 1931 the Gandhi–Irwin Pact; 1928 the Simon Commission protests.

Yaad rakhein: 1930 – 6 April – Dandi – 78 followers – 'a pinch of salt shook an empire'.

Answer: (C) 1930

Concept: The Eighth Schedule lists the officially recognised languages of India.

1. Originally 14 languages; Sindhi (1967), Konkani, Manipuri, Nepali (1992) and Bodo, Dogri, Maithili, Santhali (2003, 92nd Amendment) took the total to 22.
2. No addition has been made since 2003, so as on 30 June 2024 the number is 22.

Yaad rakhein: 14 → 15 → 18 → 22; the 2003 additions spell BDMS (Bodo, Dogri, Maithili, Santhali).

Answer: (B) 22

Concept: NCERT classifies India's industrial regions into eight major regions and thirteen minor regions.

1. Major regions: Mumbai–Pune, Hugli, Bangalore–Tamil Nadu, Gujarat, Chota Nagpur, Vishakhapatnam–Guntur, Gurgaon–Delhi–Meerut, Kollam–Thiruvananthapuram.
2. Minor regions include the Brahmaputra Valley (Assam), Ambala–Amritsar, Saharanpur–Muzaffarnagar–Bijnor, Indore–Dewas–Ujjain, Jaipur–Ajmer, Kolhapur–South Kannada, etc.

Yaad rakhein: 8 major, 13 minor; north-eastern Brahmaputra valley is a minor (tea, oil) region.

Answer: (D) Brahmaputra valley

Concept: Article 13 is the backbone of judicial review for Fundamental Rights.

1. Art. 13(1): all pre-constitutional laws inconsistent with Fundamental Rights are void to that extent; Art. 13(2): the State shall not make post-constitutional laws taking away these rights, and such laws are void – so statement 1 is correct.
2. Statement 2 restates this: laws inconsistent with or in derogation of Fundamental Rights are null and void – correct.
3. Art. 13(4) (24th Amendment) keeps constitutional amendments under Art. 368 outside this article.

Yaad rakhein: Art. 13 = 'laws' includes ordinances, bye-laws, customs; both old and new laws are tested against Part III.

Answer: (B) Both 1 and 2

Concept: Tea needs warm, humid climate, 150–300 cm rain and well-drained hill slopes.

1. Assam (Brahmaputra valley) and the Darjeeling hills along with other north-eastern hills produce the bulk of Indian tea; Assam alone gives over half.
2. Aravali, central plateau and Thar are dry regions unsuited to tea; the other tea zone is the Nilgiri hills in the south.

Yaad rakhein: Tea = Assam, Darjeeling, Nilgiri; Coffee = Karnataka (Chikmagalur).

Answer: (A) North-Eastern Hills

Concept: UNESCO's Man and the Biosphere (MAB) Programme is governed by the International Co-ordinating Council (MAB Council), to which member states are elected.

1. In November 2025, during UNESCO's 43rd General Conference, Oman was elected to the MAB International Co-ordinating Council, strengthening its global environmental role.
2. The MAB Programme (1971) manages the World Network of Biosphere Reserves; India has 12 reserves in this network.

Yaad rakhein: MAB = Man and the Biosphere (UNESCO, 1971) – biosphere reserves; IUCN handles the Red List.

Answer: (D) UNESCO Man and the Biosphere Council

Concept: The GST Council (Article 279A, 101st Amendment) decides by a three-fourths majority of weighted votes.

1. Weightage: Central Government $=\frac{1}{3}$ of the votes cast; all State Governments together $=\frac{2}{3}$.
2. A decision needs at least $\frac{3}{4}$ of the weighted votes, so neither the Centre alone nor the States alone can push a decision through.
3. Quorum: half of the total members.

Yaad rakhein: 279A – Centre $\frac{1}{3}$, States $\frac{2}{3}$, decision $\frac{3}{4}$, quorum $\frac{1}{2}$.

Answer: (C) Centre = $\frac{1}{3}$, States = $\frac{2}{3}$

Concept: $\text{Mean}=\frac{\sum f_i{x}_i}{\sum f_i}$.

1. $\sum f_i=57+23+95+14+96=285$.
2. $\sum f_i{x}_i=11\times 57+34\times 23+51\times 95+62\times 14+98\times 96=627+782+4845+868+9408=16530$.
3. Mean $=\frac{16530}{285}=58$.

Trick: $285\times 58=285\times 60-285\times 2=17100-570=16530$ – check the division by multiplying back.

Answer: (C) 58

Concept: For an AP of $n$ terms with common difference $d$, variance $=\frac{d^2(n^2-1)}{12}$.

1. $11,13,\dots ,71$: $n=\frac{71-11}{2}+1=31$, $d=2$.
2. Variance $=\frac{4({31}^2-1)}{12}=\frac{4\times 960}{12}=320$.
3. $m=\sqrt{320}\approx 17.89$ (since ${17}^2=289<320<324={18}^2$). Integral part $=17$.

Trick: SD of the first $n$ natural numbers is $\sqrt{\frac{n^2-1}{12}}$; multiply by $d$ for any AP – shifting the terms does not change SD.

Answer: (C) 17

Concept: Same direction → relative speed = difference of speeds; distance covered = sum of lengths.

1. Relative speed $=60-24=36\text{km/h}=36\times \frac{5}{18}=10\text{m/s}$.
2. Distance in 30 s $=10\times 30=300\text{m}$.
3. Other train $=300-120=180\text{m}$.

Trick: km/h → m/s: multiply by $\frac{5}{18}$; 36 km/h is exactly 10 m/s.

Answer: (D) 180