The first overtone frequency of an open organ pipe is equal to the fundamental frequency of a closed organ pipe. If the length of the closed organ pipe is 20 cm, the length of the open organ pipe is ________ cm.

Which Indian independence movement leader was primarily known for his philosophy and practice of non-violent civil disobedience?

Who gave the call for 'Do or Die' during the Quit India Movement in 1942?

Which of the following revolutionary pairs were imprisoned together in Cellular Jail and faced harsh conditions, contributing significantly to the Indian independence movement?