Two coherent monochromatic point sources S1 and S2 of wavelength λ=600nm are placed symmetrically on either side of the center of the circle as shown. The sources are separated by a distance d=1.8mm. This arrangement produces interference fringes visible as alternate bright and dark spots on the circumference of the circle. The angular separation between two consecutive bright spots is Δθ. Which of the following options is/are correct?