1. Which is longest river in world ?

Answer: Nile, Africa

2. Which is Highest Battle field ?

Answer: Siachin Glacier. Mastguru team Salutes to Indian soldiers.

3. Which is Longest national highway of India ?

Answer: NH-7 ( Varanasi to Kanyakumari - 2,369 km)

4. 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.

5. Which is the biggest museum in the world ?

Answer: British Museum, London

6. Which is the Largest lake of the world ?

Answer: Caspian Sea (371,000 sq km)

7. Which is the Densest populated State of India ?

Answer: West Bengal