The path difference between two identical light waves at a point Q on the screen is 3 μm. If the wavelength of the waves is 5000 Å, then at point Q there is a:

The Dandi March, also known as the Salt Satyagraha, was led by which influential leader?

Which act formally granted independence to India, marking the end of British rule?

Who was the key figure in establishing the Indian National Congress?