Subject :NSO Class : Class 5
Which of these statements is correct?
AAll weather changes take place in stratosphere.
BTroposphere is known as cold layer.
CRadio signals are transmitted by ionosphere.
DJet planes usually fly in exosphere.
Ans 1:
Class : Class 7
Answer C
Ans 2:
Class : Class 5
The straw is not empty; there is air inside the straw.When we dip the straw in any liquid and suck on one end of the straw, we are sucking the air out of the straw (it goes into our mouth). Now the atmosphere is pushing down on the liquid in the glass, so the liquid rises into the straw from the other end, and goes into our mouth.If we do not suck on the straw, the liquid will not rise in the straw. That means the air inside the straw is applying pressure on the liquid and not letting it rise.That means Option C is the right answer â Air exerts pressure.
Ans 3:
Class : Class 6
Ans is C because ions help in transmitting radio signals and ions are found in ionosphere.