1. Which is the highest waterfall in the world ?

Answer: Angel, Venezuela

2. Which is the longest wall in world ?

Answer: Great wall of China

3. 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.

4. Which is the longest day in the year ?

Answer: June 21

5. Which is the largest Zoo in India ?

Answer: Zoological Gardens, Alipur, Kolkata

6. Which is the state largest by area in India ?

Answer: Rajasthan

7. Which is smallest state by area of India ?

Answer: Goa