1. 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.

2. Which is the lightest gas ?

Answer: Hydrogen

3. Which is the brightest planet ?

Answer: Venus

4. Which is the longest Platform ?

Answer:

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

5. Which is largest continent ?

Answer: Asia

6. Which is the largest Zoo in India ?

Answer: Zoological Gardens, Alipur, Kolkata

7. Which is the shortest day in the year ?

Answer: December 22