MEDIUM
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Non-luminous objects _____.

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Important Questions on Light, Shadows and Reflections

MEDIUM
Why is the ratio of the velocities of light of wavelengths 4000 Å & 8000 Å in vacuum 1:1? Which of the above wavelengths has a higher frequency?
EASY
In visible light wavelength of _____ colour is minimum. 
EASY

What do you understand by monochromatic light and polychromatic light?

HARD
For a concave lens of focal length f, the relation between object and image distance u and v, respectively, from its pole can best be represented by (u=v is the reference line):
EASY

Name the portion of the electromagnetic spectrum in between ultraviolet and infrared regions.

HARD
The correct representation of wavelength intensity relationship of an ideal black body radiation at two different temperatures T1 and T2 is
HARD

The following graph depicts the inverse of magnification versus the distance between the object and lens data for a setup. The focal length of the lens used in the setup is

Question Image

Distance between the object and the lens m

EASY
An electromagnetic wave having wavelength 5000Ao will lie in which region of electromagnetic spectrum? 
EASY
Which colour of the light has the longest wavelength?
EASY
The refractive index of the material of lens are 1.56 and 1.53 for yellow and red colours of light respectively. If the focal length of lens for yellow colour is 20 cm then calculate the focal length of lens for red colour.
HARD

How fast would a rocket have to go relative to an observer for its length to be corrected to 99% of its length at rest? c=3×108ms-1

EASY

The radii of curvature of the faces of a double convex lens made of glass, are 10 cm and 15 cm. Its focal length is 12 cm.

a Find the refractive index of glass

b Calculate its new focal length if the lens is completely immersed in water ( Refractive index of water is 43)

EASY
The correct arrangement of colors in the descending order of their wavelength
EASY
The speed of light in denser medium is _____ than speed in rarer medium.
MEDIUM
A compound microscope consists of an objective lens of focal length 1 cm and an eye piece of focal length 5 cm with a separation of 10 cm. The distance between an object and the objective lens, at which the strain on the eye is minimum is n40cm. The value of n is.......
EASY
A carrot looks orange in colour because of the β carotene molecule in it. This means that the β carotene molecule absorbs light of wavelengths,