Q&A: practice questions with answers

Concept: Dissolving a gas in a liquid is an exothermic process, so by Le Chatelier's principle, lowering temperature favours dissolution.

1. Hence solubility of gases increases as temperature decreases.
2. That is why cold water holds more dissolved oxygen and warm soda goes flat faster.

Yaad rakhein: Gas + cold liquid = more soluble (cold drinks keep fizz).

Answer: (C) increases

Concept: Dr Harsh Vardhan, Union Minister of Health and Family Welfare, was elected Chairman of the WHO Executive Board on 22 May 2020.

1. He succeeded Dr Hiroki Nakatani of Japan.
2. India was nominated to the 34-member Board by the WHO South-East Asia group.

Yaad rakhein: WHO board chair = Health Minister Harsh Vardhan (2020).

Answer: (B) Health and Family Welfare

Concept: Infrared waves are called heat waves because they are readily absorbed by matter and raise its temperature.

1. They are emitted by hot bodies and the Sun; used in remote controls, night vision, physiotherapy.
2. Gamma rays and X-rays are high-energy penetrating radiations; light waves are visible light.

Yaad rakhein: IR = heat waves; UV = chemical rays.

Answer: (A) Infra-red waves

Concept: In the second Modi (NDA-2) government, Dr S. Jaishankar became External Affairs Minister on 30 May 2019.

1. He is a former Foreign Secretary and a Rajya Sabha member from Gujarat.
2. Nirmala Sitharaman – Finance; Ravi Shankar Prasad – Law & Justice, IT; Nitin Gadkari – Road Transport & Highways (2020).

Yaad rakhein: Diplomat-turned-minister = Jaishankar = MEA.

Answer: (B) Subrahmanyam Jaishankar

Concept: In a galvanic (voltaic) cell, oxidation occurs at the anode and reduction at the cathode.

1. In the Daniell cell, Zn is oxidised at the anode: $\text{Zn}\to {\text{Zn}}^{2+}+2e^{-}$.
2. Electrons pile up there, so the anode is negative; they flow to the cathode (+).
3. Diode and triode are electronic devices, not half-cells.

Trick: ‘An Ox, Red Cat’ – Anode Oxidation, Reduction Cathode.

Answer: (D) anode

Concept: Anil Kumar Manibhai Naik, Chairman of Larsen & Toubro (L&T), received the Padma Vibhushan in 2019.

1. The field was Trade and Industry – Infrastructure, for building L&T into an engineering giant.
2. He had earlier received the Padma Bhushan (2009).

Yaad rakhein: L&T chief = Trade & Industry (Infrastructure).

Answer: (C) Trade and Industry - Infrastructure

Concept: ‘The Man-Eater of Malgudi’ (1961) is a novel by R.K. Narayan, set in his fictional town Malgudi.

1. Other Malgudi works: Swami and Friends, The Guide, Malgudi Days.
2. R.K. Laxman, his younger brother, was a cartoonist (The Common Man).

Yaad rakhein: Malgudi = R.K. Narayan; Common Man = R.K. Laxman.

Answer: (B) RK Narayan

Concept: Inventory change = production − sales. A firm plans a certain inventory level.

1. If sales rise unexpectedly, goods are sold out of stock beyond the plan.
2. So inventory falls without planning – unplanned decumulation.
3. An unexpected fall in sales gives unplanned accumulation.

Trick: Sales ↑ unexpectedly → stock ↓ unplanned.

Answer: (B) unplanned decumulation of inventory

Concept: Kadsa is a folk dance of Jharkhand performed by women who carry a Kalash (pot) on their heads.

1. It is performed in agricultural/harvest festivities; men accompany with drums.
2. Kalasha = sacred pot; Kamandalu = ascetic's water pot; Kapala = skull bowl.

Yaad rakhein: Kadsa → Kalash on head.

Answer: (A) Kalasha

Concept: Adam Smith wrote ‘An Inquiry into the Nature and Causes of the Wealth of Nations’ (1776).

1. He is called the Father of Economics; the book introduced the ‘invisible hand’ and division of labour.
2. Keynes – General Theory (1936); Marshall – Principles of Economics (1890).

Yaad rakhein: 1776 – Wealth of Nations – Adam Smith.

Answer: (D) Adam Smith

Concept: According to ISFR 2019 (Forest Survey of India), total forest + tree cover is 24.56% of India's geographical area.

1. Forest cover = 21.67%; tree cover = 2.89%; $21.67+2.89=24.56$.
2. Area: about $8.07$ lakh ${\text{km}}^2$.

Trick: ISFR 2019: 21.67 + 2.89 = 24.56.

Answer: (C) 24.56

Concept: C. Rajagopalachari (Rajaji) was the first and only Indian Governor-General (1948–50) and founded the Swatantra Party (1959).

1. He was a senior Congress leader.
2. In 1954 he was among the first recipients of the Bharat Ratna – not the Padma Shri.
3. So statement (C) is NOT true.

Yaad rakhein: Rajaji = first Indian Governor-General + first Bharat Ratna (1954).

Answer: (C) He was the first recipient of the Padma Shree Award

Concept: Kohlrausch's law of independent migration of ions: ${\Lambda }_m^{\circ }={\nu }_{+}{\lambda }_{+}^{\circ }+{\nu }_{-}{\lambda }_{-}^{\circ }$.

1. Each ion contributes independently to the limiting molar conductivity.
2. It helps find ${\Lambda }_m^{\circ }$ of weak electrolytes like acetic acid.
3. Schrödinger, Dirac – quantum mechanics; Feynman – quantum electrodynamics.

Yaad rakhein: Conductivity at infinite dilution → Kohlrausch.

Answer: (C) Kohlrausch

Concept: Gandhiji joined the Khilafat Movement (led by Ali brothers) with the Non-Cooperation Movement (1920) to unite Hindus and Muslims.

1. The Khilafat issue was the British treatment of the Ottoman Caliph after World War I.
2. Gandhi felt a joint struggle could end colonial rule (‘Swaraj in one year’).

Yaad rakhein: NCM + Khilafat = Hindu–Muslim unity (1920).

Answer: (D) Khilafat Movement

Concept: Benign tumours stay confined to their original site, do not spread and cause little damage.

1. Malignant tumours grow rapidly, invade nearby tissues and spread to other organs (metastasis) – this is cancer.
2. Premalignant means changes that may later turn cancerous.

Yaad rakhein: Benign = harmless/local; Malignant = spreading.

Answer: (A) benign

Concept: The Kakori train robbery (9 August 1925) was carried out by the Hindustan Republican Association (HRA) to fund armed revolution.

1. Leaders included Ram Prasad Bismil, Ashfaqulla Khan, Rajendra Lahiri, Chandrashekhar Azad.
2. HRA was founded in 1924; renamed HSRA in 1928. INA (1942) and Gadar Party (1913) are different.

Yaad rakhein: Kakori 1925 = HRA (Bismil, Ashfaqulla).

Answer: (A) Hindustan Republican Association

Concept: The Ektara (‘one string’) is a single-string plucked instrument made of bamboo and a dried gourd.

1. It is used by folk singers, e.g. in Maharashtra and by Bauls of Bengal.
2. Edakka – Kerala drum; Esraj – bowed string instrument; Ekkalam – wind horn of Tamil Nadu.

Yaad rakhein: Ek = one, tar = string → Ektara.

Answer: (B) Ektara

Concept: Assam lies at the centre of the north-east and touches seven states/countries around it.

1. North: Bhutan and Arunachal Pradesh; East: Nagaland and Manipur.
2. South: Meghalaya, Tripura, Mizoram and Bangladesh; West: West Bengal (via the Siliguri corridor).

Yaad rakhein: Only Assam borders all other NE ‘sisters’ except Sikkim.

Answer: (D) Assam

Concept: The Coinage Act, 2011 empowers the Government of India to mint coins.

1. Section 6 allows coins of denomination not higher than ₹1,000.
2. Coins are issued by the Government, while notes are issued by RBI.

Yaad rakhein: Coinage Act 2011 → coins up to ₹1,000.

Answer: (D) ₹1,000

Concept: Refraction is the bending of light when it passes obliquely from one medium to another, due to change in its speed.

1. From rarer to denser medium (air → glass) the ray bends towards the normal.
2. Reflection = bouncing back in the same medium; diffraction = bending around obstacles/edges.

Yaad rakhein: Pencil looks bent in water / pool looks shallow → refraction.

Answer: (B) refraction