mathematics

Telephone numbers in India

Telephone numbers in India is a mathematics topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Telephone numbers in India rather than just read about it. In short: Telephone numbers in India are administered under the National Numbering Plan of 2003 by the Department of Telecommunications of the Government of India. The numbering plan was last updated in 2015.

Key takeaways

Telephone numbers in India belongs to mathematics; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Telephone numbers in India to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Telephone numbers in India from memory before moving on to harder problems.

Reference excerpt

Telephone numbers in India are administered under the National Numbering Plan of 2003 by the Department of Telecommunications of the Government of India. The numbering plan was last updated in 2015. The country code "91" was assigned to India by the International Telecommunication Union in the 1960s.

Fixed-line (landline) numbers Subscriber trunk dialling (STD) codes are assigned to each city, town and village. These codes can be between 2 and 8 digits long, with the largest metropolitan areas and cities having the shortest (two-digit) codes:

11 - New Delhi, Delhi 22 - Mumbai, Maharashtra 33 - Kolkata, West Bengal 44 - Chennai, Tamil Nadu 20 - Pune, Maharashtra 40 - Hyderabad, Telangana 79 - Ahmedabad, Gujarat 80 - Bengaluru, Karnataka Second-tier cities and metropolitan areas, as well as large or particularly significant towns have three-digit area codes:

120 - Ghaziabad and Noida, Uttar Pradesh 124 - Gurugram, Haryana 129 - Faridabad, Haryana 135 - Dehradun, Uttarakhand 141 - Jaipur, Rajasthan 160 - Kharar, Punjab 161 - Ludhiana, Punjab 172 - Chandigarh Capital Region, Chandigarh, Punjab and Haryana[1] 175 - Patiala, Punjab 181 - Jalandhar, Punjab 183 - Amritsar, Punjab 191 - Jammu, Jammu & Kashmir 194: - Srinagar, Jammu & Kashmir 233 - Sangli, Maharashtra 240 - Aurangabad, Maharashtra 241 - Ahmednagar, Maharashtra 250 - Vasai-Virar, Maharashtra 251 - Kalyan-Dombivli, Maharashtra 253 - Nashik, Maharashtra 257 - Jalgaon, Maharashtra 260 - Daman, Dadra and Nagar Haveli and Daman and Diu 261 - Surat, Gujarat 265 - Vadodara, Gujarat 343 - Durgapur, West Bengal 413 - Puducherry, Puducherry 422 - Coimbatore, Tamil Nadu 431 - Tiruchirappalli, Tamil Nadu 435 - Kumbakonam, Tamil Nadu 452 - Madurai, Tamil Nadu 462 - Tirunelveli, Tamil Nadu 469 - Thiruvalla, Pathanamthitta District, Kerala 471 - Thiruvananthapuram, Kerala 474 - Kollam, Kerala 477 - Alappuzha, Kerala 478 - Cherthala, Alappuzha District, Kerala 481 - Kottayam, Kerala 483 - Malappuram, Kerala 484 - Kochi, Kerala 485 - Muvattupuzha, Ernakulam District, Kerala 486 - Pathanamthitta, Kerala 487 - Thrissur, Kerala 490 - Thalassery, Kannur District, Kerala 495 - Kozhikode, Kerala 497 - Kannur, Kerala 512 - Kanpur, Uttar Pradesh 522 - Lucknow, Uttar Pradesh 532 - Prayagraj, Uttar Pradesh 542 - Varanasi, Uttar Pradesh 551 - Gorakhpur, Uttar Pradesh 562 - Agra, Uttar Pradesh 581 - Bareilly, Uttar Pradesh 591 - Moradabad, Uttar Pradesh 621 - Muzaffarpur, Bihar 612 - Patna, Bihar 641 - Bhagalpur, Bihar 657 - Jamshedpur, Jharkhand 712 - Nagpur, Maharashtra 721 - Amravati, Maharashtra 724 - Akola, Maharashtra 751 - Gwalior, Madhya Pradesh 761 - Jabalpur, Madhya Pradesh 820 - Udupi, Karnataka 821 - Mysore, Karnataka 824 - Mangalore, Karnataka 831 - Belgaum, Karnataka 836 - Hubli-Dharwad, Karnataka 863 - Guntur, Andhra Pradesh 866 - Vijayawada, Andhra Pradesh 870 - Warangal, Telangana 891 - Visakhapatnam, Andhra Pradesh 3192 - Port Blair, South Andaman Island, Andaman and Nicobar Islands 4896 - Kavaratti, Lakshadweep

The first-ever long-distance subscriber trunk dialing (STD) call in India was made between the cities of Kanpur and Lucknow in 1960. The total length of all phone numbers (area code and the phone number) is constant at 10 digits. For example, the number 7513200000 signifies the area code 751 (the area code for Gwalior) followed by the phone number. Fixed-line or landline numbers are at most 8 digits long.

Fixed-line operators Due to the availability of multiple operators offering fixed-line (landline) services (either wired or wireless), there is an operator code for each telephone number, which is the first digit in the phone number.

For example, a number formatted in the style (020) 3xxx-xxxx represents a fixed-line number in Pune operated by Jio, while (011) 2xxx-xxxx is a fixed-line number in Delhi operated by MTNL, and (07582) 2xx-xxx is a fixed-line number in Sagar, Madhya Pradesh operated by BSNL.

Format for dialling fixed-line numbers No prefix is required to call from one landline to another within the same area code, as variable-length dialling rules apply. A prefix of the number zero + the area code is required to dial from a landline phone in one STD code area to another. The same prefix of the number zero + the area code is required to dial any fixed-line number in India from a mobile phone, irrespective of the area code. For example, to dial a landline number in Gwalior, one would have to dial

from a landline in Gwalior: the phone number from a landline in Mumbai: 0751 and then the phone number from any mobile phone in India: 0751 and then the phone number from outside India: +91, then 751, and then the phone number Before 10 March 2009, as per Department of Telecommunications memorandum dated 9 February 2009. there were some exceptions to this general rule for STD areas falling close to each other (within a radius of 200 kilometre), where "0" can be replaced with "95" e.g. to dial Delhi from Gurgaon, one dials 9511+landline number.

Mobile numbers

A typical mobile number in India is "+91 xxxx-nnnnnn". The first four digits initially indicated an operator's code, while the remaining six digits are unique to the subscriber. However, with mobile number portability in place, the first four digits no longer indicate a particular operator.

Short code There are many businesses in the Indian market who rent keywords on a monthly basis, whose characters on a typical mobile phone keypad represent short codes. Short codes are five digits in length and have to start with the digit '5' like 58888 as of 2007. Previously, they were four-digit in number and could be of any combination, like 8888 or 7827. The current five digits can be extended by three digits further representing 3 additional characters. Messages sent to these short codes are commonly referred to as Premium Rate SMS Messages and have a cost per message depending on the operator as well as the service and the company.

Telemarketing Telemarketers have been issued 10-digit telephone numbers starting with 140 (140XXXXXXX) by the Department of Telecommunications on TRAI's request.

Notes 1.^The Chandigarh Capital Region is a metropolitan area that consists of areas in the union territory of Chandigarh, and the states of Punjab and Haryana.

References

External links Department of Telecommunications, Government of India Telecom Regulatory Authority of India India National Numbering Plan of 2003

Illustrations

Worked examples

Example 1 — a first encounter with Telephone numbers in India

Start with the simplest possible case. Write down what Telephone numbers in India claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In mathematics, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Telephone numbers in India before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Telephone numbers in India ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Telephone numbers in India

In research: Telephone numbers in India appears in mathematics research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Telephone numbers in India in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Telephone numbers in India is common in secondary-school and first-year university syllabi. It links to neighbouring topics India communications-related lists, Telephone numbers by country, Telephone numbers in India, so understanding it makes those chapters shorter.
In everyday life: Look for Telephone numbers in India outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Telephone numbers in India in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Telephone numbers in India means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Telephone numbers in India out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Telephone numbers in India in simple terms?

Telephone numbers in India are administered under the National Numbering Plan of 2003 by the Department of Telecommunications of the Government of India. The numbering plan was last updated in 2015.

Why does Telephone numbers in India matter?

Because it connects several mathematics ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Telephone numbers in India?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Telephone numbers in India.