62.
Green house effect is the heating up of the Earth's atmosphere which is due to

63.
Visible light has a higher frequency than

64.
Which of the following has the longest wavelength?

65.
Night photography and photopraphy in mist and fog are possible using

66.
A car parked in the sun with its windows closed gets terribly hot inside. This is due to

67.
To measure the speed of an approaching car a police officer shines

68.
The device used for measuring the wavelength of X-rays is

69.
If the wavelengths corresponding to ultraviolet, visible and infrared radiations are given as lUV, lVIS and lIR respectively, then which of the following gives the correct relationship among these wavelengths?

70.
Transition ions absorb light in :