The average density of earth expressed in g/cm³ is

1. 5.5
2. 2.7
3. 11
4. 4.3

Which of the following discontinuity is found between crust & mantle?

1. Conrad
2. Gutenberg
3. Mohorovicic
4. Lehmann

Give reasons for the following:

Inner core is solid although the temperature is high.

Give reasons for the following:

Core is working as a magnetic field.