AP EAPCET 08-Jul-2022 Shift 2 Paper

In a Young's double slit experiment, the slits are separated by 0.28mm and the screen is placed 1.4m away from the slits. The distance between the central bright fringe and the 4‌th ‌ order bright fringe is measured to be 1.2cm. The wavelength of light used in this experiment is