A layer in the Earth's atmosphere called Ionosphere facilitates radio communication. Why? 1. The presence of ozone causes the reflection of radio waves to Earth. 2. Radio waves have a very long wavelength. Which of the statements given above is fare correct? [CSAT 2011]

Related MCQs

• Which of the following is/are correct in matching the layer of atmosphere and its characteristic ? 1. Troposphere : weather phenomena 2. Stratosphere : ozone layer 3. Ionosphere : radio waves reflected to earth's surface 4. Mesosphere : Aurorae
• Consider the following statements: 1. Nearly 99 percent of the total mass of the atmosphere lies within 30 km of the Earth's surface. 2. The proportion of ozone in the atmosphere increases to a maximum at about 60 km from Earth's surface. Which of the statements given above is/are correct? [IAS 2008]
• Westerlies in southern hemisphere are stronger and persistent than in northern hemisphere. Why? 1. Southern hemisphere has less landmass as compared to northern hemisphere. 2. Coriolis force is higher in southern hemisphere as compared to northern hemisphere. Which of the statements given above is fare correct? [CSAT 2011]
• Which of the following are true regarding ionosphere? 1. It is the uppermost layer of atmosphere 2. The molecules and atoms of nitrogen and oxygen in this layer absorb a part of solar radiation and become ionized 3. This layer is responsible for reflecting back the radio wave~ transmitted from the earth
• Consider the following statements: 1. P - waves are the first seismic waves to reach a place 2. S - waves travel only through liquids 3. Arrival time of P and S - waves is used to locate the epicentre 4. Richter scale is a logarithmic scale Which of the statements given above are correct? [IAS2004]
• Consider the following statements: 1. Troposphere varies in its thickness between equator and poles. 2. Stratosphere does not experience Normal Lapse Rate. 3. Ozone layer occurs in the Mesophere. 4. Ionosphere lies between Stratosphere and Mesosphere Which of these statements are correct? [NDA 2003]
• Consider the following statements regarding the atmosphere of the earth: 1. It is enveloping the earth because of gravity. 2. Its density decreases with increasing height from the surface of the earth. 3. Its characteristic composition is same throughout its height. 4. Amount of pressure it exerts on earth's surface at sea level is called one atm sphere. Which of these statements are correct? [CDS 2001]
• The jet aircrafts fly very easily and smoothly in the lower stratosphere. What could be the appropriate explanation? 1. There are no clouds or water vapour in the lower stratosphere. 2. There are no vertical winds in the lower stratosphere. Which of the statements given above is/are correct in this context? [CSAT 2011]
• Consider the following statements: 1. Biodiversity is normally greater in the lower latitudes as compared to the higher latitudes, 2. Along the mountain gradients, biodiversity is normally greater in the lower altitudes as compared to the higher altitudes. Which of the statements given above is/are correct? [CSAT 2011]
• What is the difference between asteroids and comets? 1. Asteroids are small rocky planetoids, while comets are formed of frozen gases held together by rocky and metallic material. 2. Asteroids are found mostly between the orbits of Jupiter and Mars, while comets are found mostly between Venus and Mercury. 3. Comets show a perceptible glowing tail, while asteroids do not. Which of the statements given above is/are correct? [CSAT 2011]