A laser is placed in front of a double slit as shown in figure 6b . The laser emits light of wavelegth 589 nm . The slits act as coherent sources of progressive waves . The waves superpose and an interference an pattern is observered on the screen 2.6 m from the slits . i. Describe the pattern of fringes observed in the screen ii. The disctance between the centres of the bright fringes is 5.1 mm . Calculate the slit seperation of the double slits . iii. What would happen to the fringe spacing if the slit seperation was halved ? Justify your answer .

A laser is placed in front of a double slit as shown in figure 6b . The laser emits light of wavelegth 589 nm . The slits act as coherent sources of progressive waves . The waves superpose and an interference an pattern is observered on the screen 2.6 m from the slits . i. Describe the pattern of fringes observed in the screen ii. The disctance between the centres of the bright fringes is 5.1 mm . Calculate the slit seperation of the double slits . iii. What would happen to the fringe spacing if the slit seperation was halved ? Justify your answer .