Who is known as Indian Bismarck?

Ali Akbar plays which of the following musical instruments?
 

Who is the first non-Indian to receive the Bharat Ratna?

Consider the following paragraph:
He was seriously injured in a police Lathi charge in Lahore during a demonstration against Simon Commission, for which he subsequently died in November $1928$. Later, the British officer responsible for the lathi-charge on him was shot dead by Bhagat Singh and Rajguru.
The revolutionary referred to in the above paragraph is ____.

Sound waves produce echo due to ____.

Diamond and Graphite are ____.

Which of the following is essential for blood clotting?

ELISA test is used to detect ____.