In a Youngs double experiment, the slits are $$1.5\ mm$$ apart. When the slits are illuminated by a monochromatic light source and the screen is kept $$1\ m$$ apart from the slits, width of $$10$$ fringes is measured as $$3.93\ mm$$. Calculate the wavelength of light used. What will be the width of $$10$$ fringes when the distance between the slits and the screen is increased by $$0.5\ m$$. The source of light used remains the same.