Intelligence Bureau Jio-II/Tech Tier 1 Result Out

Important from UPSC POV

Good morning future GCs and LCs🌅.
Just 100 days to go for the exam.
Work hard towards your goal .🍀

⚔️Remember" Nothing changes if nothing changes"

New year to ho Gya guys.
Let's study the concept of International Date line.

🌨️The International Date Line is an imaginary line that roughly follows the 180° longitude and is used to determine the change of date.

☘️Key Points for CDS /NDA/Capf
🪵It is not a straight line → it zigzags to avoid cutting countries, islands, and island groups.
🪴It lies mostly over the Pacific Ocean.
🍀There is no change in time, only change in date.
🌱It is fixed by international agreement, not by any natural feature.

🌻Rule of Date Change
🌅Cross IDL from East → West → Add 1 day
🌊Cross IDL from West → East → Subtract 1 day.

🪨Relation with Greenwich Mean Time (GMT)
IDL is 180° opposite to the Prime Meridian (0°).

⚡⚡Why does it zigzag?
To keep:
Same country
Same island group on the same date
Example:
Russia, Alaska, Kiribati islands are not divided by different dates internally.


Padh ke bhagna nahi hai niche question attempt karo jaldi se ab 👇👇👇

Article 39 of INDIAN CONSTITUTION

Attention aspirants !!!!

💥13 Sunday =13 paper series .

(Jan -4, Feb-4, March-5, total 13 Sundays)
From this Sunday onwards on each Sunday solved previous year paper will be shared of CDS english and G.S.
You have to solve them and then match answer with answer key and explanation.

It will give you sense of accountability .
Whole week you have to work , improve and Sunday test gives you the reality check enhancing your preparation.

This will enhance your abilities of time management, handling pressure and question solving .

Are you ready warriors 🔱

Someone have done immense amount of hardwork for u all❤️
Make use of it❤️
Aur karna sabko h 🔥

Govt keeps small savings interest rates unchanged for March quarter.

On 1 January 2026, Air Marshal Nagesh Kapoor took over as the 50th Vice Chief of the Air Staff succeeding Air Marshal Narmdeshwar Tiwari who superannuated on 31 December 2025.

Denmark's national postal service, PostNord, has delivered its final letter, marking the end of a 400-year tradition as digital communication replaces physical mail. The move makes Denmark the first country to conclude that letter delivery is no longer essential—or economically viable—in the digital age.

High , ☠ how you are?

Bihar Police Havildar Clerk Notification Out✅

https://bpssc.bihar.gov.in/Notices/Advt.%20No.-01-2026%20Havildar%20Clerk%20D.R..pdf

📍Banks of the Narmada River, Khargone district, Indore Division, Madhya Pradesh

Food poisoning kills 200 parrots in MP’s Khargone district

Wildlife warden Tony Sharma told media —

Around 25 were initially , Today crossed 200 Parrots along with several pigeons, diamond doves and sparrows were also found dead.

Jaldi aa jao sare 🐴🐯🦁
Aaj ghumne chalenge inside of the earth 🌍🦖.

Interior of earth🌏

🍀 SOURCES OF INFORMATION ABOUT EARTH’S INTERIOR

🔹 ⚡Direct Sources (Limited Use)

Mining (few km only)

Deep drilling projects

❌ Not reliable for deep interior

🔹 Indirect Sources (MOST IMPORTANT)

Seismic waves (Primary source)

Gravity anomalies

Magnetic field

Meteorites

📌 UPSC fact: Seismic waves are the most reliable source.


🌳STRUCTURE OF THE EARTH

🧱 CRUST

Outermost layer

🌿Thickness:

Continents: 30–70 km

Oceans: 5–10 km



🌴Composition:

Continental crust → SIAL (Silica + Aluminium)

Oceanic crust → SIMA (Silica + Magnesium)

🪨 MANTLE

Extends from Moho to ~2900 km

Accounts for ~84% of Earth’s volume

Rich in silicates of magnesium and iron

🔸 Asthenosphere❄️

Part of upper mantle

Semi-molten / plastic in nature

Responsible for plate movements

📌 Plastic ≠ fully molten

🔥 ) CORE🌑

Extends from 2900 km to Earth’s centre (6371 km)

Composition: Nickel + Iron (NIFE)

Outer Core🌓
Liquid state

Source of Earth’s magnetic field

Inner Core🌖

Solid state
Solid due to extremely high pressure

Discontinuity Boundary☄️

•Conrad- Upper & Lower crust
•Mohorovičić (Moho) -Crust & Mantle
•Gutenberg -Mantle & Core
•Lehmann -Outer Core & Inner Core

SEISMIC WAVES (HIGHEST WEIGHTAGE)🏖️

🔹 P-Waves (Primary)
🌊
Fastest seismic waves

Travel through solids, liquids & gases

🔹 S-Waves (Secondary)🏞️

Slower than P-waves

Travel through solids only

❌ Cannot pass through liquid

🔹 Surface Waves🌪️

Travel along Earth’s surface

Most destructive

SHADOW ZONES⛱️

S-wave shadow zone: Beyond 103° from epicentre

P-wave shadow zone: Between 103°–142°/105°-140°


☘️Significance:

Proves liquid nature of outer core

Confirms layered structure of Earth


🦞TEMPERATURE & PRESSURE INSIDE EARTH

Both increase with depth

Causes:

Radioactive decay

Residual heat

Pressure

Inner core temperature: ~5000–6000°C


🕸️EARTH’S MAGNETIC FIELD
🐾
Generated due to convection currents of molten iron in the outer core

Known as Dynamo Theory


❌ Not due to mantle convection ❌ Not due to Earth’s rotation alone

🚨CRUST THICKNESS (PYQ AREA)

Thickest under fold mountains (Himalayas ≈ 70 km)

Thinnest under oceans

🛑🚦KEY UPSC TRAPS (MUST REMEMBER)

⚓Asthenosphere = plastic, not molten

🛹Inner core = solid due to pressure

🚇Magnetic field = outer core, not mantle

🚤S-waves = liquid barrier proof

🚀Most reliable evidence = seismic waves


Ghumne se kam.nahi chalta
Pyqs bhi solve karne padte hai mittr👇👇👇👇