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प्रश्न
The small ozone layer on top of the stratosphere is crucial for human survival. Why?
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उत्तर
The small ozone layer on the top of the atmosphere is crucial for human survival because it absorbs harmful ultraviolet radiations present in sunlight and prevents it from reaching the Earth’s surface.
संबंधित प्रश्न
Identify the part of the electromagnetic spectrum which is suitable for radar system used in aircraft navigation.
Use the formula λm T= 0.29 cm K to obtain the characteristic temperature ranges for different parts of the electromagnetic spectrum. What do the numbers that you obtain tell you?
Give the range of wavelength of the electromagnetic waves visible to us.
Name the region beyond the violet end of the spectrum called.
Can X-rays be used for photoelectric effect?
X-ray and visible light travel at the same speed in vacuum. Do they travel at the same speed in glass?
Iron emits Kα X-ray of energy 6.4 keV. Calculate the times taken by an iron Kα photon to cross through a distance of 3 km.
(Use Planck constant h = 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
The electron beam in a colour TV is accelerated through 32 kV and then strikes the screen. What is the wavelength of the most energetic X-ray photon?
(Use Planck constant h = 6.63 × 10-34 Js= 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
Name the scientist who discovered
X-rays
Name any two electromagnetic waves which have a frequency higher than that of violet light. State one use of each.
Answer briefly.
Give two uses of ultraviolet rays.
Answer briefly.
What are radio waves?
X-rays, gamma rays and microwaves travelling in a vacuum have ______.
A radio can tune to any station in the 7.5 mHz to 12 MHz band. What is corresponding wave length band.
SONAR emits which of the following waves?
Why does microwave oven heats up a food item containing water molecules most efficiently?
Identify the electromagnetic radiation and write its wavelength range, which is used to kill germs in water purified. Name the two sources of these radiations.
Name two electromagnetic waves of wavelength smaller than that of violet light.
