Consider a thin, long, insulator-coated conducting wire carrying current I. It is wound once around an insulating thin disc of radius R to bring the wire back on the same side. The magnitude of the magnetic field at the centre of the disc is equal to:

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?