1. Which is the deepest lake of the world ?

Answer: Lake Baikal

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 Largest library in the world ?

Answer: United State Library of Congress, Washington D.C.

5. Which is the largest Zoo in India ?

Answer: Zoological Gardens, Alipur, Kolkata

6. Which is the biggest country in Area ?

Answer: Russia

7. Which is the highest dam in India ?

Answer: Tehri Dam on Bhagirathi River in Uttarakhand (Height of 260 metres)