In the following questions, Statement of assertion (A) is followed by a statement of reason (R). 1. If both assertion and reason are true and the reason is the correct explanation of the assertion, then mark. 2. If both assertion and reason are true but the reason is not the correct explanation of the assertion, then mark. 3. If assertion is true statement but reason is false, then mark. 4. If both assertion and reason are false statements then mark.
Assertion: In high latitudes one sees colorful curtains of light hanging down from high altitudes. Reason: The high energy charged particles from the sun are deflected to Polar Regions by the magnetic field of the earth.A) 1
B) 2
C) 3
D) 4
Correct Answer: A
Solution :
Earth is surrounded by its magnetic field in space called magnetosphere, which forms a barrier to Solar wind. The solar wind pressure strongly compresses the magnetosphere on the dayside and draws it out into an extremely long tail on the night side of the earth. Since, the charged particles of the solar wind cannot cross the earths magnetic field lines they flow around the magnetosphere. This forms a standing shock wave in space upstream of the earth. The magnetosphere and the solar wind form an enormous electrical dynamo where large and complicated electrical currents flow. These electrons descend down to altitudes of 100 - 300 km they may collide with the atmospheric gas causing it to glow. This is the basic cause of aurora. Note that the plasma sheet is only connected to magnetic field lines from the earths Polar Regions on the night sight, which explains why the aurora is mostly seen only at high latitudes at night.
You need to login to perform this action.
You will be redirected in
3 sec
