Q&A: practice questions with answers

Concept: Bharatiya Antariksh Station (BAS) is India's planned indigenous space station, approved by the Union Cabinet in September 2024 as part of the expanded Gaganyaan programme.

1. Its first module (BAS-1) is targeted for launch by 2028 and the full station by 2035; an Indian crewed Moon landing is targeted for 2040.
2. It will orbit at about 400 km and support long-duration human spaceflight and microgravity research.
3. Telescopes (AstroSat) or Mars missions (Mangalyaan) are separate programmes.

Yaad rakhein: BAS 2035 – Moon 2040 (Amrit Kaal space roadmap).

Answer: (B) To establish an indigenous space station

Concept: SI prefixes denote powers of ten: centi $={10}^{-2}$, milli $={10}^{-3}$, micro $={10}^{-6}$, nano $={10}^{-9}$, pico $={10}^{-12}$.

1. ${10}^{-9}$ corresponds to the prefix nano (symbol n), e.g. 1 nanometre $={10}^{-9}$ m.
2. Milli is one-thousandth, centi one-hundredth and micro one-millionth, so none of them matches.

Yaad rakhein: Descending by 3: milli (−3) → micro (−6) → nano (−9) → pico (−12); "nano" ~ "nine".

Answer: (B) Nano

Concept: Work done $W=Fs\cos \theta$, where $\theta$ is the angle between the force and the displacement. Its sign depends only on $\cos \theta$.

1. $\theta$ between $0^{\circ }$ and ${90}^{\circ }$: $\cos \theta >0$ → positive work (e.g. pushing a box forward).
2. $\theta ={90}^{\circ }$: $\cos {90}^{\circ }=0$ → zero work (e.g. gravity on a horizontally moving body).
3. $\theta$ between ${90}^{\circ }$ and ${180}^{\circ }$: $\cos \theta <0$ → negative work (e.g. friction, which acts opposite to motion).

Yaad rakhein: Force "helping" motion → +W; force "opposing" motion (friction, braking) → −W; force at right angle → zero.

Answer: (C) Force and displacement are between ${90}^{\circ }$ and ${180}^{\circ }$

Concept: Tantia Tope (Ramchandra Pandurang) was Nana Saheb's general and the most skilled guerrilla commander of the 1857 Revolt, fighting at Kanpur, Kalpi and Gwalior with Rani Lakshmibai.

1. After the fall of Gwalior (June 1858) he carried on guerrilla warfare in Central India for nearly a year.
2. He was betrayed by his associate Man Singh of Narwar, captured in April 1859 and hanged at Shivpuri (Sipri) on 18 April 1859.

Yaad rakhein: Lakshmibai fell June 1858; Tantia Tope hanged April 1859 – the last major leader to be executed.

Answer: (B) 1859

Concept: The Junagadh (Girnar) rock inscription of 150 CE is the earliest long inscription in chaste Sanskrit and was issued by the Saka (Western Kshatrapa) ruler Rudradaman I.

1. It records the repair of the Sudarshana lake, originally built under Chandragupta Maurya and improved under Ashoka, after it burst in a storm.
2. It also praises Rudradaman's conquests, including victories over the Satavahana king Satakarni.
3. Nahapana was an earlier Kshaharata Kshatrapa; Kanishka and Kadphises I were Kushana rulers.

Yaad rakhein: Junagadh = Rudradaman = Sudarshana lake = first Sanskrit inscription.

Answer: (D) Rudradaman I

Concept: In April 2025 the Department of Science and Technology announced that researchers at JNCASR, Bengaluru had developed a super-fast-charging sodium-ion (Na-ion) battery.

1. The battery uses a NASICON-type anode (Na_1.0V_0.25Al_0.25Nb_1.5(PO₄)₃), engineered by nanosizing, carbon coating and aluminium doping.
2. It can charge to about 80% in just 6 minutes and lasts over 3,000 charge cycles, offering a cheap, abundant alternative to lithium-ion.

Yaad rakhein: JNCASR sodium-ion → "6 minutes to 80%" – sodium is cheap and plentiful in India.

Answer: (D) 6 minutes

Concept: Globalisation, one of the three pillars of the 1991 New Economic Policy (Liberalisation, Privatisation, Globalisation), means integrating the national economy with the world economy.

1. It involves reducing trade barriers, allowing foreign investment (FDI/FII), free flow of goods, services, technology and capital.
2. Options about self-sufficiency only, closing trade or raising barriers describe the opposite – protectionism of the pre-1991 era.

Yaad rakhein: LPG 1991: Liberalisation = fewer controls, Privatisation = less government ownership, Globalisation = join the world market.

Answer: (D) Integrate Indian economy with global markets

Concept: The Gupta age is called the golden age of Sanskrit literature; its greatest poet-dramatist Kalidasa is traditionally placed in the court of Chandragupta II 'Vikramaditya' (c. 375–415 CE).

1. Kalidasa is counted among the Navaratnas (nine gems) of Vikramaditya's court; his works include Abhijnanashakuntalam, Meghadutam, Raghuvamsham and Kumarasambhavam.
2. Samudragupta was a patron of Harishena; Chandragupta I founded the Gupta era (319–20 CE); Skandagupta repelled the Hunas.

Yaad rakhein: Kalidasa – Vikramaditya – Chandragupta II – Ujjain – Navaratna.

Answer: (B) Chandragupta II

Concept: Harappan metal-workers cast bronze figurines by the lost-wax (cire perdue) technique.

1. A wax model is coated with clay; on heating, the wax melts and drains out, leaving a hollow mould into which molten bronze is poured.
2. The famous bronze 'Dancing Girl' from Mohenjodaro and the bronze buffalo and bull figures were made this way.
3. Sand and die casting are modern industrial techniques, not Harappan.

Yaad rakhein: Harappan bronze = lost-wax; Dancing Girl = Mohenjodaro; bronze = copper + tin.

Answer: (C) Lost-Wax Technique

Concept: Judicial activism is the proactive role of the judiciary in protecting citizens' rights and compelling the executive to act, going beyond strict interpretation of law.

1. Public Interest Litigation (PIL), developed in India by Justices P.N. Bhagwati and V.R. Krishna Iyer around 1979–80, relaxed the rule of locus standi so that any public-spirited person can approach the court for the disadvantaged.
2. Through PILs courts have ordered action on bonded labour, prison reforms, environment (M.C. Mehta cases) – a classic example of judicial activism.
3. Judicial restraint is the opposite – deference to the legislature and executive.

Yaad rakhein: PIL = Bhagwati + Krishna Iyer = Judicial Activism (Hussainara Khatoon case, 1979).

Answer: (C) Judicial Activism

Concept: Lord Curzon (Viceroy 1899–1905) passed several measures that Indians saw as attacks on their self-respect and institutions, fuelling early nationalism.

1. The Indian Universities Act, 1904 (based on the Raleigh Commission, 1902) reduced elected senate members, increased government nominees and brought colleges under strict official control – nationalists condemned it as an attempt to curb growing political consciousness among educated Indians.
2. Together with the Calcutta Corporation Act (1899), the Official Secrets Act (1904) and the Partition of Bengal (1905), it provoked intense opposition.
3. The other options describe trivial routine changes that would not provoke a national movement.

Yaad rakhein: Curzon's "four blows": Calcutta Corporation 1899, Universities Act 1904, Official Secrets Act 1904, Bengal Partition 1905.

Answer: (D) Enacting the Universities Act of 1904, which tightened official control over Indian higher education.

Concept: Newton's second law: resultant force $F=m\times a$, with mass in kg and acceleration in ${\text{m/s}}^2$ giving force in newton (N).

1. $m=10\text{kg}$, $a=5{\text{m/s}}^2$.
2. $F=10\times 5=50\text{N}$.
3. Joule is the unit of work/energy, so options in joule are wrong on units alone.

Trick: Check units first – force is always in newton; $1\text{N}=1{\text{kg·m/s}}^2$.

Answer: (D) 50 Newton

Concept: The pancreas (islets of Langerhans) secretes two hormones controlling blood sugar: insulin from beta cells and glucagon from alpha cells.

1. Insulin lowers blood glucose by stimulating cells (muscle, fat, liver) to take up glucose and store it as glycogen; its deficiency causes diabetes mellitus.
2. Glucagon does the opposite – raises blood glucose by breaking down glycogen.
3. Thyroxine (thyroid) and cortisol (adrenal cortex) are not pancreatic hormones.

Yaad rakhein: Insulin = "in" – pushes glucose into cells (sugar down); Glucagon = "gone" – releases glucose (sugar up).

Answer: (D) Insulin

Concept: The Constitution (106th Amendment) Act, 2023 – the Nari Shakti Vandan Adhiniyam – reserves one-third of seats for women in the Lok Sabha, State Legislative Assemblies and the Delhi Assembly.

1. It was passed in September 2023 in the new Parliament building; the reservation will take effect only after a census and the delimitation exercise based on it, and will last 15 years (extendable).
2. 103rd (2019) – 10% EWS reservation; 104th (2020) – extended SC/ST reservation in legislatures, ended Anglo-Indian nomination; 105th (2021) – restored states' power to identify OBCs.

Yaad rakhein: 106 = Nari Shakti (women, 33%); 105 = OBC list; 104 = SC/ST extension; 103 = EWS.

Answer: (A) 106th Amendment

Concept: PM Modi visited France on 10–12 February 2025, co-chairing the AI Action Summit in Paris with President Macron and visiting Marseille and the ITER fusion project at Cadarache.

1. Outcomes included the India-France Declaration on Artificial Intelligence, the launch of the India-France Year of Innovation 2026, a declaration of intent on cybersecurity/digital cooperation and the inauguration of India's consulate in Marseille.
2. No "India-France Infrastructure Pact" was signed – that option is not part of the visit's outcomes.

Yaad rakhein: Feb 2025 Paris = AI Action Summit (India co-chair) + Innovation Year 2026 + Marseille consulate; the next AI summit is hosted by India (2026).

Answer: (D) India-France Infrastructure Pact

Concept: When parts of the stock are sold at different profit/loss rates, the overall profit % is the weighted average of the rates (weights = fraction of goods, since cost per unit is the same).

1. Fractions: first $50\%$, then $40\%$ of the remaining $50\%$ = $20\%$, the rest = $30\%$.
2. Overall profit $=0.5\times 21+0.2\times 36-0.3\times 29=10.5+7.2-8.7=9$.

Trick: Think of total cost as ₹100: profit = $10.5+7.2-8.7=9$ rupees = $9\%$ directly.

Answer: (C) 9

Concept: A number leaving the same remainder $r$ on division by several numbers = (multiple of their LCM) $+r$.

1. $\text{LCM}(6,14,7)=42$.
2. Largest 4-digit multiple of 42: $9999=42\times 238+3$, so $42\times 238=9996$. But $9996+5=10001$ is 5-digit, so take $42\times 237=9954$.
3. Required number $=9954+5=9959$.

Trick: Always check that adding the remainder does not push the number past 9999 – that is exactly the trap here.

Answer: (B) 9959

Concept: SP $=$ MP $\times$ (product of discount multipliers); compare SP with CP.

1. Let CP $=100$, MP $=140$.
2. SP $=140\times 0.82\times 0.95=140\times 0.779=109.06$.
3. Profit $=9.06\%$.

Trick: Combined discount of 18% and 5% $=18+5-\frac{18\times 5}{100}=22.1\%$; then $140\times 0.779$.

Answer: (D) 9.06%

Concept: Successive profits multiply: final price $=\text{CP}\times (1+p_1)(1+p_2)$.

1. First sale: $200\times 1.10=220$.
2. Second sale: $220\times 1.15=253$.

Trick: Net % $=10+15+\frac{10\times 15}{100}=26.5\%$ → $200\times 1.265=253$.

Answer: (A) ₹253

Concept: Divisible by 8 ⇔ last three digits divisible by 8; divisible by 9 ⇔ digit sum divisible by 9.

1. Last three digits 512 $=8\times 64$ ✓ for any $y$.
2. Digit sum $=6+y+5+1+2=14+y$; must be 18 → $y=4$.

Trick: The 8-test does not involve $y$ here, so only the 9-test decides.

Answer: (C) 4