1. Who is the Indian-American who was sworn-in as the U.S. Surgeon-General?

2. Who has been appointed as the Director General of Railway Protection Force (RPF)?

3. Which day does United Nations (UN) observes World Book and Copyright Day around the world?

4. India and which other country began a 10-day naval exercise named 'Varuna' on 23 April 2015?

5. National Institute of Electronics and Information Technology (NIELIT) has signed a memorandum of understanding (MoU) with which e-commerce giant to roll out digital marketing courses?

6. Which country has been named the happiest country in the world as per latest World Happiness Report?

7. Calbuco volcano has erupted recently for the first time in more than 42 years, Which country did it erupt in?

8. Which telecom company announced unlimited free calling scheme during night hours from its fixed line phones to any operator including mobile phones anywhere in the country from 1 May?

9. Which union ministry has launched a scheme called ‘Operation Five Minutes’?

10. Which Union Ministry has recently received an ISO 9001:2008 certification from the British Standards Institute?