A man is 6 ft tall. In order to see his entire image, he requires a plane mirror of minimum length equal to :
6 ft
12 ft
2 ft
3 ft
Interference is possible in
light waves only
sound waves only
Both light and sound waves
Neither light nor sound waves
A telescope has an objective lens of 10cm diameter and is situated at a distance of one kilometre from two objects. Find out the minimum distance between these two objects, which can be resolved by the telescope, when the mean wavelength of light is 5000 Å.
0.5 m
5 m
5 mm
5 cm
For the given incident ray as shown in figure, the condition of total internal reflection of the ray will be satisfied if the refractive index of block will be
One face of a rectangular glass plate 6 cm thick is silvered. An object held 8 cm in front of the first face, forms an image 12 cm behind the silvered face. The refractive index of the glass is :
0.4
0.8
1.2
1.6
2 convex lenses
2 concave lenses
1 convex, 1 concave lens
1 convex and 1 plane mirror
Which of the following phenomenon is not common to sound and light waves?
Interference
Diffraction
Coherence
Polarisation
Which of the following phenomenon is not explained by Huygen's construction of wavefront?
Refraction
Reflection
Origin of spectra
The hypermetropia is a
short-sight defect
long-sight defect
bad vision due to old age
None of the above
Colours of thin soap bubbles are due to :s
Dispersion