An object is placed in front of a spherical mirror 18 whose

P and Q as two equally intense coherent sources emitting radiations of wavelength 20m as shown in the figure The separation PQ is 5m and phase of P is ahead of the phase of Q by 900 A B and C are three distant points of observation equidistant from the mid point of PQ The intensity of radiations of A B C will be the ratio B C 1 0 1 4 PQ A

experiment with slits of equal intensity as shown in the figure Take O as origin and the Y axis as indicated If average intensity between D y and Y2 equal n times the 4d intensity of maxima then n equals take average over phas difference S os 21 90 1 a D 4d 2 d 1 S 2 T 1 2 D IY O AN A y 2axa X X 1 b 2 1 2 d 1

3 3 4 4 40 The equation y 4 2 sin 6t 3x represents wave motion with 1 amplitude 6 units 2 amplitude 4 units 3 wave speed 2 units 4 wave speed 1 2 units

14 A child AB is star straight plane mirror fixed to a vertical wall His father CD is standing behind him as shown in the fig The height of the father is double the height of the child What is the minimum length of the mirror required so that the child can completely see his own image and his father s image in the mirror Given that the height of father is 2H Assume eye level at the top most point D C A B H H wall 12

In Young s double slit experiment the slits are 0 5 mm apart and interference pattern is observed on a screen placed at a distance of 1 0 m from the plane containing the slits If wavelength of the incident light is 6000 then the separation between the third bright fringe and the central maxima is AMU 1995 a 4 0 mm c 3 0 mm b 3 5 mm d 2 5 mm

Two parallel slits 0 6 mm apart are illuminated by light source of wavelength 6000 The distance between two consecutive dark fringes on a screen 1 m away from the slits is JIPMER 1999 a 1 mm c 0 1 m b 0 01 mm d 10 m

In Young s double slit experiment two slits are illuminated with separation between them as b The screen is at a distance d b from slits At a point P on the screen directly in front of one of the slits certain wavelengths are missing Match the options of the columns Column I A At P wavelength b d is B At P wavelength b 5d is C D The wavelength 26 3d at a point on screen at some other distance b 3 from central maxima Column II P missing Q not missing Wavelength 2b 3d is R X b missing at a point Q on screen which is at a distance X from central maxima S X 3b 4

In a Young s double slit experiment the fringe width will remain same if D distance between screen and plane of slits d separation between two slits and wavelength of light used Bihar MEE 1995 a Both and D are doubled b Both d and D are doubled c Dis doubled but d is halved d 2 is doubled but d is halved 1

8 A convex lens of focal length f 10 cm is cut through a dimeteral plane into two semicircular halves In doing so glass of 0 5 mm thickness is lost The two halves are then joined together This lens is placed symmetrically 5 cm in front of a slit which is illuminated with light of wavelength 5000 A A screen is placed on the other side of the lens at a distance of 90 cm from the lens perpendicular to the optical axis of the lens Find total number of bright fringes formed

In Young s experiment the width of the fringes obtained with light of wavelength 6000 A is 2 0 mm What will be the fringe width if the entire apparatus is immersed in a liquid of refractive index 4 3