Pick out the longest wavelength from the following types of radiations.
Blue light
Gamma rays
X-rays
Red light
A convex lens is dipped in a liquid whose refractive index is equal to the refractive index of the lens. Then its focal length will
become small, but non-zero
remain unchanged
become zero
become infinite
An astronomical telescope of ten fold angular magnification has a length of 44 cm. The focal length of the objective is
440 cm
44 cm
40 cm
If two mirrors are kept inclined at 60° to each other and a body is placed at the middle, then total number of images formed, is
six
The wavelength of light of frequency 100Hz is
2 × 106 m
3 × 106 m
4 × 106 m
5 × 106 m
A beam of monochromatic light is refracted from vacuum into a medium of refractive index 1.5. The wavelength of refracted light will be
dependent on intensity of refracted light
same
smaller
larger
A convex lens and a concave lens, each having same focal length of 25 cm, are put in contact to form a combination of lenses. The power in diopters of the combination is
infinite
2 convex lenses
2 concave lenses
1 convex, 1 concave lens
1 convex and 1 plane mirror
Diameter of human eye lens is 2mm. What will be the minimum distance between two points to resolve them, which are situated at a distance of 50m from eye? [The wavelength of light is 5000 Å]
2.32 m
4.28 mm
1.25 cm
12.48 cm
Interference is possible in
light waves only
sound waves only
Both light and sound waves
Neither light nor sound waves
