If two waves represented by and interfere at a point, the amplitide of the resulting wave will be about
1. 7
2. 6
3. 5
4. 3.5
What is the minimum thickness of a sopa film needed for constructive interference in reflected light, if the light incident on the film is 750 nm? Assume that the index for the film is n = 1.33
1. 282 nm
2. 70.5 nm
3. 141 nm
4. 387 nm
A thin mica sheet of thickness m and refractive index is introduced in the path of the light from upper slit. The wavelength of the wave used is . The central bright maximum will shift
1. 2 fringes upward
2. 2 fringes downward
3. 10 fringes upward
4. None of these
A monochromatic beam of light falls on YDSE apparatus at some angle (say ) as shown in the figure. A thin sheet of glass is inserted in front of the lower slit . The central bright fringe (path difference = 0) will be obtained
1. at O
2. above O
3. below O
4. anywhere depending on angle , thickness of plate t and refractive index of glass
In the Young's double slit experiment, the intensities at two points on the screen are respectively . If is located at the centre of a bright fringe and is located at a distance equal to a quarter of fringe width from , then is
1. 2
2. 3
3. 4
4. None of these
In Young's double slit experiment the 10th maximum of wavelength is at a distance of from the central maximum. When the wavelength of the source is changed to , 5th maxiumum is at a distance from its central maximum . The ratio is
1.
2.
3.
4.
Two light rays having the same wavelength in vacuum are in phase initially . Then the first ray travels a path through a medium of refractive index while the second ray travels a path of length through a medium of refractive index . The two waves are then combined to produce interference . The phase difference between the two waves is
1.
2.
3.
4.
In Young's double slit experiment the two slits acts as coherent sources of equal amplitude A and wavelength . In another experiment with the same set up the two slits are sources of equal amplitude A and wavelength but are incoherent. The ratio of the intensity of light at the mid point of the screen in the first case to that in the second case is
1. 4:1
2. 1:1
3. 2:1
4. 1:4
In YDSE the y-coordinates of central maxima and 10 th maxima are 2 cm and 5 cm respectively. When the YDSE apparatus is immersed in a liquid of refractive index 1.5 the corresponding y-coordinates will be
1. 2 cm, 7.5 cm
2. 3 cm, 6 cm
3. 2 cm, 4 cm
4. 4/3 cm, 10/3 cm
In Young's double slit experiment, white light is used. The separation betwwen the slits is b. The screen is at a distance d(d>>b) from the slits. Some wavelengths are missing exactly in front of one slit. These wavelengths are
1.
2.
3.
4.
Two ideal slits are at a distance d apart and illuminated by light of wavelength passing through an ideal source slit S placed on the line through as shown. The distance between the planes of slits and the source slit is D.
A screen is held at a distance D from the plane of the slits. The minimum value of d for which there is darkness at O is
1.
2.
3.
4.
A beam of light parallel to central line AB is incident on the plane of slits. The number of minima obtained on the large screen is . Now if the beam is tilted by some angle as shown in figure, then the number of minima obtained is
1.
2.
3.
4. will be zero
Lights of wavelength 589.3 nm is incident normally on two slits of separation 0.1 mm width 0.01 nm. The angular width of the central diffraction maximum at a distance of 1 m from the slits is
1. 0.68
2. 0.34
3. 2.05
4. None of these
In the adjacent diagram, CP represents a wavefront and AO and BP, the corresponding two rays. Find the conditions of for constructive interference at P between the rays BP and reflected ray AOP
1.
2.
3.
4.
Two coherent sources separated by distance d are radiating in phase having wavelength . A detector moves in a big circle around the two sources in the plane of the two sources. The angular position of n = 4 interference maxima is given as
1.
2.
3.
4.