1. Which is Longest Dam in India ?

Answer: Hirakod Dam (Orissa)

2. Which is the longest Platform ?

Answer:

Gorakhpur railway station, Uttar Pradesh, India (1355.40 meters)

3. Which is the Densest populated State of India ?

Answer: West Bengal

4. Which is largest Dome in India ?

Answer: Gol Gumbaz (Karnataka)

5. Which is Place of heaviest rainfall ?

Answer: Mausinram (Meghalaya)

6. Where is largest Archipelago ?

Answer: Indonesia

7. Which is highest dam in world ?

Answer:

Jinping-I Dam - 305 m (1,001 ft) in China on Yalong river.
Second Highest is Nurek Dam 300 m (980 ft) Tajikistan on Vakhsh river.