Q&A: practice questions with answers

Concept: Self-induction is the production of an induced emf in a coil when the current in the same coil changes.

1. Changing current → changing magnetic flux through the coil itself → back emf $\epsilon =-L\frac{dI}{dt}$ ($L$ = self-inductance, unit henry).
2. Emf in a coil due to current change in a nearby coil is mutual induction (option A).

Yaad rakhein: Self = own current; Mutual = neighbour's current.

Answer: (C) Induction of EMF in a coil due to a change in its own current

Concept: Operation Sindoor (7 May 2025) was India's strike on terror camps in Pakistan and PoK after the Pahalgam attack.

1. The official media briefings were led by Colonel Sofiya Qureshi (Army) and Wing Commander Vyomika Singh (IAF), along with Foreign Secretary Vikram Misri.
2. Their briefings were noted as a strong message of women's role in the armed forces.

Yaad rakhein: Sindoor briefing → two women officers: Col. Sofiya Qureshi & Wg Cdr Vyomika Singh.

Answer: (D) Colonel Sofiya Qureshi and Wing Commander Vyomika Singh

Concept: Fractional distillation separates a mixture of liquids whose boiling points are different, using a fractionating column.

1. Crude oil is heated; fractions such as petroleum gas, petrol, kerosene, diesel and lubricating oil condense at different heights of the column.
2. Heavy, high-boiling fractions like lubricating oil are separated by the same process (done under reduced pressure).
3. Filtration, sublimation and extraction cannot separate such liquids.

Yaad rakhein: Petroleum refining = fractional distillation.

Answer: (D) Fractional distillation

Concept: Each Veda has an Upaveda (subsidiary knowledge).

1. Rigveda – Ayurveda; Yajurveda – Dhanurveda; Samaveda – Gandharvaveda; Atharvaveda – Shilpaveda (Arthashastra by some).
2. Gandharvaveda deals with music and dance – fitting, because the Samaveda is the Veda of melodies (chants).

Yaad rakhein: Sama = music → Gandharva (music).

Answer: (C) Samaveda

Concept: The Indian Ocean Conference is organised by India Foundation with partner countries to discuss Indian Ocean cooperation.

1. The 8th Indian Ocean Conference was held in Muscat, Oman on 16–17 February 2025.
2. Its theme was "Voyage to New Horizons of Maritime Partnership"; External Affairs Minister S. Jaishankar addressed it.

Yaad rakhein: Muscat 2025 → "Voyage to New Horizons".

Answer: (C) Voyage to New Horizons of Maritime Partnership

Concept: Precision agriculture robots use cameras and AI to spot diseased plants and spray pesticide only where it is needed.

1. Researchers of IIT Kharagpur developed such an agricultural robot that detects plant diseases and applies pesticides precisely.
2. Targeted spraying cuts chemical use, cost and harm to the environment and farm workers.

Yaad rakhein: Agri-robot for disease detection → IIT Kharagpur.

Answer: (D) Indian Institute of Technology Kharagpur (IIT-KGP)

Concept: The Kherwar (Sapha Har) movement was a Santhal reform-and-revolt movement of the 1870s in the Santhal Parganas.

1. It was led by Bhagirath Manjhi, who called for a return to the "golden age" of tribal self-rule and opposed revenue settlement.
2. Sidhu Murmu led the Santhal Hul (1855), Birsa Munda the Ulgulan (1899–1900) and Tilka Manjhi the earlier revolt of 1784.

Yaad rakhein: Kherwar → Bhagirath; Hul → Sidhu–Kanhu; Ulgulan → Birsa.

Answer: (A) Bhagirath Manjhi

Concept: Bori is a Lower Palaeolithic site in the Kukadi river valley, Pune district.

1. Bori lies in Maharashtra; tools found in volcanic ash layers there were dated to about 1.4 million years, among the oldest in India.
2. Hence it is often called one of the earliest Lower Palaeolithic sites of India.

Yaad rakhein: Bori → Pune → Maharashtra.

Answer: (D) Maharashtra

Concept: Sashastra Seema Bal (SSB) is a Central Armed Police Force under the Ministry of Home Affairs guarding the Nepal and Bhutan borders.

1. As of May 2025, Amrit Mohan Prasad (IPS) was the Director General of SSB.
2. Daljit Singh Chawdhary headed SSB earlier and moved on to head the BSF.

Yaad rakhein: SSB → Nepal & Bhutan border; DG (May 2025) Amrit Mohan Prasad.

Answer: (A) Amrit Mohan Prasad

Concept: BIMSTEC members: Bangladesh, Bhutan, India, Myanmar, Nepal, Sri Lanka and Thailand.

1. The 6th BIMSTEC Summit was held in Bangkok, Thailand on 4 April 2025 under Thailand's chairmanship.
2. Its theme was "Prosperous, Resilient and Open BIMSTEC"; the Bangkok Vision 2030 was adopted.

Yaad rakhein: 6th BIMSTEC → Bangkok.

Answer: (C) Bangkok

Concept: In Mauryan administration the village (grama) was the smallest unit, headed by a headman.

1. In North India the village headman was called the Gramika (Gramani), assisted by village elders.
2. Gavunda and Pattakila were terms for village headmen in the Deccan/South India in later periods.

Yaad rakhein: Grama → Gramika (North); Gavunda/Pattakila → South.

Answer: (B) Gramika

Concept: Khelo India Youth Games (KIYG) are national multi-sport games for young athletes under the Khelo India scheme.

1. The 7th KIYG was held in May 2025 in Bihar (Patna, Rajgir and other cities), with some events in New Delhi.
2. Maharashtra topped the medal table.

Yaad rakhein: KIYG 2025 → Bihar (+ New Delhi).

Answer: (D) Bihar

Concept: The Integrated Rural Development Programme (IRDP) aimed to give self-employment assets to the rural poor through subsidy and bank credit.

1. IRDP was started in 1978–79 and extended to all blocks of India from 2 October 1980, as a key programme of the Sixth Plan (1980–85).
2. The Sixth Plan focused on removal of poverty and employment generation.

Yaad rakhein: IRDP → Sixth Plan (1980); later merged into SGSY (1999).

Answer: (D) Sixth Plan

Concept: The Public Accounts Committee (PAC) is a financial committee of Parliament (22 members: 15 Lok Sabha + 7 Rajya Sabha).

1. Its main job is to examine the audit reports of the Comptroller and Auditor General (CAG) on government accounts.
2. Its chairman is traditionally from the Opposition. Budget estimates are examined by the Estimates Committee, not PAC.

Yaad rakhein: PAC = "watchdog" that studies CAG reports.

Answer: (A) To review CAG audit reports

Concept: In May 1857 the sepoys from Meerut marched to Delhi and sought a unifying symbol for the revolt.

1. They proclaimed the old Mughal emperor Bahadur Shah II (Zafar) as the Emperor of Hindustan and leader of the revolt.
2. Nana Saheb (Kanpur), Rani Lakshmibai (Jhansi) and Tantia Tope were regional leaders, not the symbolic head.

Yaad rakhein: Symbolic leader of 1857 → Bahadur Shah Zafar.

Answer: (D) Bahadur Shah II

Concept: Check each option by division or divisibility rules.

1. $20$: number must end in $0$ – $726179$ ends in $9$, so no. $28$: an odd number cannot be divisible by $28$.
2. $726179÷23$: $23\times 31573=631460+94719=726179$, remainder $0$.
3. $726179÷29$ leaves remainder $29\times 25040=726160$, $726179-726160=19\ne 0$.

Trick: Odd number → strike out every even divisor first ($28$, $20$), then test only $23$ and $29$.

Answer: (A) $23$

Concept: A quadrilateral is cyclic if its opposite angles are supplementary (sum ${180}^{\circ }$).

1. $\angle A+\angle C={47}^{\circ }+{133}^{\circ }={180}^{\circ }$ and $\angle B+\angle D={66}^{\circ }+{114}^{\circ }={180}^{\circ }$.
2. Opposite angles are supplementary, so A, B, C, D lie on a circle – cyclic quadrilateral.
3. Not a parallelogram/rhombus (opposite angles not equal); not a trapezium (adjacent pairs ${47}^{\circ }+{66}^{\circ }$, ${66}^{\circ }+{133}^{\circ }$ etc. are not ${180}^{\circ }$, so no sides parallel).

Trick: Add opposite angles: both pairs $={180}^{\circ }$ → cyclic.

Answer: (C) Cyclic quadrilateral

Concept: Surface area of a sphere $=4\pi r^2$.

1. $r=24\text{cm}$, so $r^2=576$.
2. $S=4\pi \times 576=2304\pi {\text{cm}}^2$.

Trick: $4r^2=(2r{)}^2={48}^2=2304$ – square the diameter.

Answer: (C) $2304\pi {\text{cm}}^2$

Concept: Let mother's age $=M$ and daughter's age $=D$; form two linear equations.

1. $3M=5D+29$ and $2D=M-2\Rightarrow M=2D+2$.
2. Substitute: $3(2D+2)=5D+29\Rightarrow 6D+6=5D+29\Rightarrow D=23$.
3. $M=2\times 23+2=48$; difference $=48-23=25$ years.

Trick: Check: $3\times 48=144$ and $5\times 23+29=144$ ✓.

Answer: (A) $25$

Concept: Write each number in prime factors; LCM = highest power of every prime.

1. $3^3\times 9^2\times 13=3^3\times 3^4\times 13=3^7\times 13$.
2. $3^2\times {13}^2\times 18=3^2\times {13}^2\times 2\times 3^2=2\times 3^4\times {13}^2$.
3. $9^3\times {13}^2\times {18}^2=3^6\times {13}^2\times 2^2\times 3^4=2^2\times 3^{10}\times {13}^2$.
4. LCM $=2^2\times 3^{10}\times {13}^2$.

Trick: Here the third number already contains the other two, so it is itself the LCM.

Answer: (B) $2^2\times 3^{10}\times {13}^2$