Pick the wrong answer in the context with rainbow
When the light rays undergo two internal reflection in a water drop , a secondary rainbow is formed
The order of colors is reversed in the secondary rainbow
An observer can see a rainbow when his front is towards the sun
Rainbow is a combined effect of dispersion , refreaction and reflection of sunlight
Two similar thin equiconvex lenses , of focal length f each , are kept coaxially in contact with each other such that the focal length of the combination is . When the space between the two lenses is filled with glycerin then the equivalent focal length is
. The ratio
2 : 1
1 : 2
2 : 3
3 : 4
In total internal reflection when the angle of incidende is equal to the critical angle for the pair of media in contact what will be angle of refraction ?
180
0
equal to angle of incidence
90
...so why is u=+10 and not -10 ? As it will be in the direction opposite to the incident rays
In a diffraction pattern due to a single slit of width 'a', the first minimum is observed at an angle 30° when light of wavelength is incident on the slit. The first secondary maximum is observed at an angle of:
The interference pattern is obtained with two coherent light sources of intensity ratio n. In the interference pattern, the ratio
will be
The angle of incidence for a ray light at a refracting surface of a prism is 45°. The angle of prism is 60°. If the ray suffers minimum deviation through the prism, the angle of minimum deviation and refractive index of the material of the prism respectively, are:
45°;
30°;
45°;
30°;
An air bubble in a glass slab with refractive index 1.5 (near normal incidence) is 5 cm deep when viewed from one surface and 3 cm deep when viewed from the opposite face. The thickness (in cm) of the slab is
8
10
12
16
A linear aperture whose width is 0.02 cm is placed immediately in front of a lens of focal length 60 cm. The aperture is illuminated normally by a
parallel beam of wavelength 5 x 10-5 cm. The distance of the first dark band of the diffraction pattern from the centre of the screen is
0.10 cm
0.25 cm
0.20 cm
0.15 cm