In which of the following activities are Indian Remote Sensing (IRS) satellites used?<br/>1. Assessment of crop productivity<br/>2. Locating groundwater resources<br/>3. Mineral exploration<br/>4. Telecommunications<br/>5. Traffic studies<br/><br/>Select the correct answer using the code given below.

1. Assessment of crop productivity — Correct. IRS satellites are widely used in agricultural remote sensing for crop acreage, condition and yield/productivity estimation.
2. Locating groundwater resources — Correct. Remote sensing helps identify groundwater potential zones through geomorphology, drainage and landform analysis.
3. Mineral exploration — Correct. IRS data are used in geological mapping and identifying mineral-bearing structures/alteration zones.
4. Telecommunications — Incorrect. Telecommunications is the role of communication satellites like INSAT/GSAT, not IRS remote sensing satellites.
5. Traffic studies — Incorrect. While satellite imagery can support urban planning, IRS satellites are not primarily used for telecommunications/traffic management in the standard UPSC sense.
Therefore, 1, 2 and 3 only are correct.