Where is the National Dairy Research Institute (NDRI), India's premier dairy research institute for dairy science and technology, located?

Introduction / Context:
National Dairy Research Institute (NDRI) is one of India's most important institutions in the field of dairy science, animal husbandry, milk processing, and agricultural research. Many competitive exams and general knowledge tests ask about the location of key national institutes, because it helps learners connect places with their specialised functions and understand India's research geography.

Given Data / Assumptions:

• The question asks for the city where the National Dairy Research Institute (NDRI) is located.
• The options given are Ludhiana, Karnal, Pantnagar and Hyderabad.
• NDRI is known as a premier institute for dairy research, education and extension.

Concept / Approach:
To answer this type of question, you rely on factual general knowledge about national-level institutes. NDRI was originally set up in Bangalore during the British period but its main campus was later shifted. Today, whenever exams refer to the location of NDRI, they mean its well known main campus in Karnal, in the state of Haryana. The approach is to recall this association and then eliminate the other cities that are better known for different institutions or universities.

Step-by-Step Solution:
Step 1: Recall that NDRI is a premier research institute dealing with dairy science, cattle breeding, milk technology and related fields. Step 2: Remember that the modern main campus of NDRI is situated in Karnal, a city in Haryana, which has become strongly linked with dairy research in India. Step 3: Compare this with the other options: Ludhiana is more famous for Punjab Agricultural University, Pantnagar for Govind Ballabh Pant University of Agriculture and Technology, and Hyderabad for several other national institutes but not NDRI. Step 4: On this basis, select Karnal as the correct location of NDRI's principal campus. Step 5: Confirm that multiple standard GK references refer to "NDRI, Karnal", which verifies the answer.

Verification / Alternative check:
You can verify the answer by checking the official website or standard government publications, where NDRI is clearly described as being headquartered at Karnal in Haryana. Older historical notes sometimes mention Bangalore because that is where the institute began, but almost all exam-oriented material and current references identify Karnal as the key location. This cross-check reinforces that Karnal is the expected exam answer.

Why Other Options Are Wrong:
Ludhiana: This city is mainly associated with Punjab Agricultural University and other agricultural research centres, not with NDRI.
Pantnagar: It is famous for Govind Ballabh Pant University of Agriculture and Technology and is a major centre for agricultural education, but it is not the home of NDRI.
Hyderabad: Hyderabad hosts many important institutions in information technology, administration and agriculture, yet the National Dairy Research Institute is not based there.

Common Pitfalls:
A common mistake is to confuse NDRI with other agricultural universities and institutes, especially if you have recently studied about them. Another pitfall is remembering only the historical origin of NDRI in Bangalore and ignoring its present headquarters. Exam questions generally expect the currently recognised main campus, so it is important to remember "NDRI, Karnal" as a fixed fact for GK preparation.

Final Answer:
The National Dairy Research Institute (NDRI) is located at Karnal in the state of Haryana, India.