UPSC Prelims Current Affairs for 4 August 2026

Magnetorheological Fluid

August 4, 2026

Magnetorheological Fluid Latest News

Recently, scientists at the Indian Institute of Technology (IIT) Patna have developed an innovative hybrid magneto-rheometer that promises to advance research and applications of magnetorheological (MR) fluids.

About Magnetorheological Fluid

It is a fluid that has good magnetic properties.
MR fluid responds to the magnetic field and changes its properties when a magnetic field is presented.
Property: These fluids can rapidly change their mechanical properties when exposed to a magnetic field, increasing in apparent viscosity, to the point of becoming a viscoelastic solid.
Composition: These fluids contain magnetic micro-sized iron particles, non-magnetic-based fluid, and some additives in order to mitigate sedimentation and agglomeration.
Carrier fluids: The various carrier fluids used in the preparation of MR fluids are mineral oil, silicon oil, castor oil, soybean oil, kerosene, synthetic oils, honge oil, organic oil, water-based oils, etc.
- However, for obtaining better vibration control, silicone oil is the most preferred one due to its higher viscosity index, lower friction characteristics, higher flash point, and higher shear strength.
The fluid can transmit force which can be controlled with an electromagnet, giving rise to its many possible control-based applications.
Potential Applications: It is ideal for adaptive technologies such as brakes, clutches, shock absorbers, vibration control systems, dampers, actuators, and medical devices.

Source: PIB

Magnetorheological Fluid FAQs

Q1: What is the main advantage of Magnetorheological Fluid (MR) fluid over Electrorheological (ER) fluid?

Ans: Requires lower energy and gives higher force

Q2: What are the carrier fluid used in MR fluid?

Ans: Mineral oil, Silicon oil, Castor oil, Soybean oil, kerosene etc.

Vikram Sarabhai Medal

August 4, 2026

Vikram Sarabhai Medal Latest News

Recently, astrophysicist Annapurni Subramaniam has been awarded the COSPAR Vikram Sarabhai Medal – 2026.

About Vikram Sarabhai Medal

It was constituted in 1990 in the honour of Vikram Sarabhai.
It is an international medal awarded to scientists from developing countries for their outstanding contributions to the field of space research.
It is awarded jointly by the Committee on Space Research (COSPAR) and the Indian Space Research Organization (ISRO).
Eligibility: For a candidate to be eligible for this award, her or his relevant work must have been carried out mainly in the five year period ending one year before the COSPAR Scientific Assembly at which the medal is to be presented.
- Annapurni Subramaniam is the only fourth Indian to receive this medal, in addition to being the first Indian woman scientist and only the third female recipient of this honour.
- Other Indian recipients: Anil Bharadwaj (2024), Gurbax Singh Lakhina (2014) and UR Rao, (1996).

Key Facts about Committee on Space Research

It was established in 1958.
It is an international body affiliated to the International Science Council and United Nations (through UN-COPUS).
COSPAR is one of the largest forums for space scientists and holds its scientific assembly biennially.

Source: IE

Vikram Sarabhai Medal FAQs

Q1: The Vikram Sarabhai Medal is awarded by whom?

Ans: It is awarded jointly by the Committee on Space Research (COSPAR) and the Indian Space Research Organization (ISRO).

Q2: The medal is named after Vikram Sarabhai who is known as?

Ans: Father of Indian Space Programme

Glaw Lake

August 4, 2026

Glaw Lake Latest News

Glaw Lake in Arunachal Pradesh's Lohit district has been designated as India's 101st Ramsar Site under the Ramsar Convention on Wetlands, making it the first Ramsar Site in Arunachal Pradesh. The announcement was made by Union Environment Minister Bhupender Yadav on 3 August 2026, marking a significant milestone in India's efforts to strengthen wetland conservation, biodiversity protection, climate resilience, and sustainable management of freshwater ecosystems.

About Glaw Lake

Location: It is located in the state of Arunachal Pradesh.
It is Arunachal Pradesh’s first designated Ramsar Site.
It is a freshwater lake in the Eastern Himalayas is a biodiversity hotspot, nestled within the Kamlang Tiger Reserve and Wildlife Sanctuary.
It is located at an elevation of 1,168 meters.
Water Source: The Lake is fed by perennial mountain streams and is surrounded by lush vegetation, supporting rich floral diversity.
Biodiversity: The wetland has over 150 tree species and 49 orchid species recorded within the site and its catchment, underscoring the ecological significance of Glaw Lake and its surrounding landscape.
- It supports high-altitude aquatic biodiversity, including endangered species such as the White-Bellied Heron and Clouded Leopard.

Key Facts about Ramsar Convention

It is an intergovernmental treaty that sets the framework for both national action and international cooperation to conserve and ensure the wise use of wetlands and their resources.
It was adopted in 1971 in the city of Ramsar in Iran and came into force in 1975.
It was the first intergovernmental agreement focused exclusively on a specific ecosystem, i.e. wetlands.
The convention rests on the three main pillars
- Conservation of wetlands of international importance,
- Promotion of the wise use of all wetlands within a country’s territory
- International co-operation on shared wetland systems and migratory species

Source: PIB

Glaw Lake FAQs

Q1: Glow Lake is located in which state?

Ans: Arunachal Pradesh

Q2: Glow Lake is situated inside which Tiger Reserve?

Ans: Kamlang Tiger Reserve

Q3: What is a Ramsar Site?

Ans: A Ramsar Site is a wetland recognized as a Wetland of International Importance under the Ramsar Convention, an international treaty adopted in 1971 for the conservation and sustainable use of wetlands.

Q4: How many Ramsar Sites are there in India as of August 2026?

Ans: As of August 2026, India has 101 Ramsar Sites, following the inclusion of Glaw Lake as the country's latest Wetland of International Importance.

Q5: Which is the first Ramsar Site in Arunachal Pradesh?

Ans: Glaw Lake is the first Ramsar Site in Arunachal Pradesh, receiving international recognition for its ecological significance and role in conserving freshwater biodiversity.

Madura Island

August 4, 2026

Madura Island Latest News

At least five people were killed and 41 remain missing after a ferry carrying 271 passengers and crew caught fire off Indonesia's Madura Island recently.

About Madura Island

It is an Indonesian island located off the northeast coast of Java.
It's separated from Java by the narrow Madura Strait.
It is known as "The Salt Island" because it produces a lot of salt.
The island covers an area of 5,290 sq.km.
Madura Island has a mostly flat landscape. There are no big mountains or huge changes in height.
Most of these people are Madurese. About 3.6 million to 4 million Madurese live on the island.
The Madura people are the third largest people group in Indonesia.
The main language spoken here is Madurese.
It is famous for its bull races held each year after the harvest.
The main towns on the island include Bangkalan in the west, followed by Sampang, Pamekasan, and Sumenep further east.
Economy:
- The principal industries are cattle raising and salt panning, the latter a government monopoly.
- Kapok, copra, and coconut oil are important products, as is teak from forests in the northwest.

News: NDTV

Madura Island FAQs

Q1: Where is Madura Island located?

Ans: Off the northeast coast of Java, Indonesia.

Q2: Which strait separates Madura Island from Java?

Ans: The Madura Strait.

Q3: Why is Madura Island known as the "Salt Island"?

Ans: Because it produces a large quantity of salt.

Q4: What type of landscape does Madura Island have?

Ans: A mostly flat landscape with no major mountains.

TRAI MyCall

August 4, 2026

TRAI MyCall Latest News

The Telecom Regulatory Authority of India (TRAI) recently launched a revamped version of "TRAI MyCall', a mobile application that enables telecom consumers to directly assess and report the voice-calling experience.

About TRAI MyCall

It is a mobile application launched by the Telecom Regulatory Authority of India (TRAI).
It is a citizen-centric digital platform that empowers telecom consumers to share real-time feedback on their voice-calling experience, along with relevant network parameters.
The feedback provided by consumers is visible to Telecom Service Providers (TSPs) as well as TRAI in an anonymised form.
This feedback provides valuable insights to TSPs, helping them identify areas where network performance needs improvement and take targeted corrective measures.
This consumer-driven approach is expected to enhance the overall Quality of Service (QoS).
The platform also strengthens evidence-based regulatory oversight by enabling TRAI to assess the Quality of Experience (QoE) across telecom networks based on real consumer feedback.
While network performance is evaluated using technical Quality of Service (QoS) parameters, the QoE perceived by consumers also provides an important perspective on service performance.
The revamped TRAI MyCall application offers several consumer-friendly features, including:
- Instant rating of voice calls through a simple 1-5 star feedback system.
- Reporting of specific issues such as call drops, echo during calls, audio delay, cross connection, voice breaking, one party unable to hear the other, and calls taking too long to connect, which shall be available to the respective service provider for corrective action.
- Automatic post-call feedback prompts for seamless participation.
- Rating and feedback history on interactive map.
- Coverage Test feature to assess signal strength.
- Multilingual support with Bhashini.

Key Facts about Telecom Regulatory Authority of India

It is a regulatory body responsible for overseeing the telecommunications industry in India.
It was established under the Telecom Regulatory Authority of India Act, 1997, passed by Parliament.
Objectives:
- To stimulate the growth and development of the telecommunication sector by creating favorable conditions.
- To provide a fair and transparent environment for telcos.
- To come up with different regulatory directions/mandates on tariffs, DTH, portability of mobile numbers, and so on.
Roles and Functions:
- It sets fair pricing standards for telecom services, such as calls, SMS, and data, to make sure they are affordable to the consumers.
- TRAI monitors the telcos and makes sure they provide high-quality services when it comes to network coverage, stability, and customer satisfaction/support.
- It recommends guidelines pertaining to licenses and permissions for new services providers as well as existing ones.
- TRAI addresses complaints and ensures the companies abide by the consumer protection laws.
- It ensures that the businesses providing telecommunication services do not engage in deceptive practices, such as false advertising and hidden charges.
- Also, it oversees that its regulations are implemented by telcos and enforces penalties on them in case of violation of regulations.
- TRAI fixes and regulates tariffs provided by telcos, which were earlier vested in the Central Government.
Composition:
- It consists of a Chairperson, a maximum of two full-time members, and two part-time members.
- Tenure: Members serve for three years or until the age of 65 years, whichever is earlier.
- Appointments are made by the Central Government.
Telecom Disputes Settlement And Appellate Tribunal (TDSAT):
- The TRAI Act was amended, establishing a TDSAT to take over the adjudicatory and dispute functions from TRAI.
- TDSAT was set up to adjudicate any dispute between a licensor and a licensee, between two or more service providers, between a service provider and a group of consumers, and to hear and dispose of appeals against any direction, decision, or order of TRAI.

News: PIB

TRAI MyCall FAQs

Q1: What is TRAI MyCall?

Ans: A mobile application launched by the Telecom Regulatory Authority of India (TRAI).

Q2: What is the primary purpose of the TRAI MyCall app?

Ans: To enable telecom consumers to provide real-time feedback on their voice-calling experience.

Q3: Who can view the feedback submitted through the TRAI MyCall app?

Ans: Telecom Service Providers (TSPs) and TRAI in anonymised form.

Q4: How does the feedback collected through TRAI MyCall help Telecom Service Providers?

Ans: It helps them identify network issues and take corrective measures.

Banderol Missile

August 4, 2026

Banderol Missile Latest News

Russia’s new low-cost S8000 Banderol cruise missile is quietly changing the air war over Ukraine’s Black Sea coast.

About Banderol Missile

The S8000 Banderol, which translates to "package" or "small parcel," is a cruise missile developed by Russia.

Banderol Missile Launch Platforms

It is primarily an air-launched munition, with the Orion unmanned aerial vehicle (UAV) serving as its primary launch platform.
The missile is also integrated for use with the Mi-28 Havoc helicopter.
However, reports indicate that Russian has developed a compact ground launcher for the S8000 Banderol, moving beyond its previous airborne carriers.

Banderol Missile Features

The missile's design prioritizes low production costs and simplified manufacturing, incorporating imported foreign components for key systems.
It is approximately 5 m long, with a wingspan of 2.2 m and a body diameter of 30 cm.
Powered by a small, commercially available Chinese turbojet engine, it can travel up to 500 km.
Its maximum speed is 620–650 km/h, and its cruising speed is 520–560 km/h.
It carries a relatively small high-explosive fragmentation warhead that includes about 50 kilograms of explosives.
The missile navigates using inertial and satellite guidance.

News: HT

Banderol Missile FAQs

Q1: What is the S8000 Banderol?

Ans: A cruise missile developed by Russia.

Q2: What is the primary launch platform of the S8000 Banderol missile?

Ans: The Orion unmanned aerial vehicle (UAV).

Q3: What type of engine powers the S8000 Banderol missile?

Ans: A commercially available Chinese turbojet engine.

Q4: What is the maximum range of the S8000 Banderol missile?

Ans: Up to 500 kilometres.

Modified Interest Subvention Scheme

August 4, 2026

Modified Interest Subvention Scheme Latest News

A third-party assessment by the Institute for Social and Economic Change (ISEC), Bengaluru said that every ₹1 invested under Kisan Credit Card– Modified Interest Subvention Scheme (KCC-MISS) contributes ₹2.30 to net value addition in the agriculture & allied sector.

About Modified Interest Subvention Scheme

It is a Central Sector Scheme launched in 2006–07 by the Government of India.
Aim: It is aimed at ensuring the availability of short-term credit to farmers at an affordable interest rate through Kisan Credit card (KCC).
Under the Scheme:
- Farmers received short-term loans of up to Rs.3 lakh through Kisan Credit Cards (KCC) at a subsidized interest rate of 7%, with 1.5% interest subvention provided to eligible lending institutions.
- Additionally, farmers repaying loans promptly are eligible for an incentive of up to 3% as Prompt Repayment Incentive (PRI) effectively reducing their interest rate on KCC loans to 4%.
- For loans taken exclusively for animal husbandry or fisheries, the interest benefit is applicable up to Rs.2 lakh.
It is implemented by the Reserve Bank of India (RBI) and the National Bank for Agriculture and Rural Development (NABARD).
It is operated through Public Sector Banks, Regional Rural Banks (RRBs), Cooperative Banks and Private Sector Banks operating in rural and semi urban areas.

Source: PIB

Modified Interest Subvention Scheme FAQ's

Q1: What is the objective of Modified Interest Subvention Scheme?

Ans: Ensure affordable credit to farmers

Q2: What is the rate of interest subvention provided to lending institutions under MISS?

Ans: 1.5%

Ethiopia

August 4, 2026

Ethiopia Latest News

Recently, a landslide triggered by heavy rainfall in Ethiopia's Amhara region killed 14 people and injured several others.

About Ethiopia

Location: It is a landlocked country in the Horn of Africa.
It lies entirely within tropical latitudes.
Bordering Countries: It is bordered by six countries namely Eritrea (North), Djibouti (Northeast), Somalia (East), Kenya (South), South Sudan and Sudan (West).
Capital City: Addis Ababa

Geographical Features of Ethiopia

Topography: The five major topographic features of the country are the Rift Valley, Western and Eastern Highlands, and Western and Eastern Lowlands.
- The Denakil Plain, in which a depression known as the Kobar Sink drops as low as 380 feet (116 metres) below sea level, is found here in its rift valley.
Climate: Most of Ethiopia has a tropical climate.
Highest Point: Mount Ras Dejen which is 4,533 m high
Major Rivers: It has three main rivers in Ethiopia are the Blue Nile, the Omo River, and the Awash River.
Lakes: Lake Tana which is located in the northwest of the Ethiopian Highlands.
Natural Resources: It has reserves of precious metals and other natural resources such as gold, potash, natural gas, copper, and platinum.

Source: TH

Ethiopia FAQs

Q1: What is the capital of Ethiopia ?

Ans: Addis Ababa

Q2: Which crop is Ethiopia famous for and is a major export?

Ans: Coffee

Baba Baidyanath Dham Temple

August 4, 2026

Baba Baidyanath Dham Temple Latest News

A large number of devotees thronged the Baba Baidyanath Dham temple in Jharkhand’s Deoghar on the first Monday of the holy month of Shravan.

About Baba Baidyanath Dham Temple

It is a Hindu temple dedicated to Lord Shiva located in Deoghar, Jharkhand.
It is one of the 12 Jyotirlingas in India.
This ancient temple has been mentioned in several ancient scriptures, such as Puranas, Vedas, Mahabharata, Ramayana, etc.

Baba Baidyanath Dham Temple History

The mythological origin of Baidyanath Dham is tied to the legend of King Demon Ravana, who was granted a boon by Lord Shiva to take a sacred Jyotirlinga to his palace in Lanka.
But he placed it on the ground in Deoghar, where the Lingam permanently resides.
Historical records suggest the temple's original construction in the 8th century by Puran Mal, an ancestor of the Nagavanshi dynasty.
Over the centuries, the temple has seen numerous renovations and expansions, reflecting various architectural styles and cultural influences.
The current structure is attributed to Raja Man Singh in the 16th century.
The temple hosts the famous Shravani Mela, one of the largest annual religious gatherings in India.

Baba Baidyanath Dham Temple Architecture

The temple showcases the classic Nagara style of North Indian architecture.
The temple complex is spread over an area of 12 acres and consists of 22 temples dedicated to various deities.
The main temple is the Baidyanath Jyotirlinga Temple, which houses the lingam of Shiva.
The temple is built of stone and has a pyramidal tower that rises to a height of 72 feet.
The temple has a simple and elegant design, with a spacious hall, a sanctum, and a vestibule.

News: DD

Baba Baidyanath Dham Temple FAQs

Q1: Where is Baba Baidyanath Dham Temple located?

Ans: Deoghar, Jharkhand.

Q2: To which deity is Baba Baidyanath Dham Temple dedicated?

Ans: Lord Shiva.

Q3: Who is believed to have originally constructed Baba Baidyanath Dham Temple?

Ans: Puran Mal, an ancestor of the Nagavanshi dynasty.

Q4: Which style of architecture is seen in Baba Baidyanath Dham Temple?

Ans: Nagara style of North Indian architecture.

Q5: Why is Baba Baidyanath Dham considered one of India's most important pilgrimage sites?

Ans: Because it is one of the 12 Jyotirlingas dedicated to Lord Shiva and hosts the annual Shravani Mela.

Dikhow River

August 4, 2026

Dikhow River Latest News

Flash floods from the Dikhow River recently submerged Assam's Nepali Khuti, a self-reliant Gorkha dairy village, within two hours, destroying homes, livestock, and livelihoods completely.

About Dikhow River

It is an important south bank tributary of the Brahmaputra River.
Course:
- It originates in the Zunheboto district of Nagaland and enters into the Assam plain through Naginimara of the Sivsagar district of Assam.
- It flows through the Sivsagar district only to join with the river Brahmaputra at Dikhowmukh on its southern bank within the district.
The total length of the river is 236 km.
The river basin is surrounded by the Brahmaputra River in the north, the Buridihing basin in the east, the Jhanji basin in the west, and the Naga Hills in the south.
The river leaves more than fifteen abandoned channels at different places in the Assam plain mostly in the form of Ox-bow Lakes.

News: RED

Dikhow River FAQs

Q1: Of which major river is the Dikhow River a tributary?

Ans: The Brahmaputra River.

Q2: Where does the Dikhow River originate?

Ans: Zunheboto district of Nagaland.

Q3: Through which district of Assam does the Dikhow River enter the Assam plain?

Ans: Sivasagar district (through Naginimara).

Q4: What is the total length of the Dikhow River?

Ans: 236 km.