(ii) Give any one evidence which points towards the existence of the Earth's
magnetic field.
Londoa magnet is attracted towards it

Londoa magnet is attracted towards it showing that there is existence of magnetic field of Earth.

Explanation:

The core of the planet Earth has it's own magnetic field and because of this there is some permanent kind of magnetization of this planet. This leads to the attracting of the magnets towards the magnetic field of planet Earth.

At the Equator, the direction of the magnetic field of Earth is pointing towards the north direction and at this point the position of the magnetic field of Earth is horizontal. This has been shown and proven with the help of a use of a compass.

answer: the exterior temperature of commercial jet planes as they leave the stratosphere and return to the ground increases steadily.

explanation:

the lower most layer of atmosphere is troposphere which extends from 0 to 12 km above the surface of the earth. the temperature initially decreases as distance is increased from the earth's surface. commercial jets fly in lower part of the stratosphere. the stratosphere extends upto 50 km. the temperature in stratosphere starts rising again due to presence of ozone which traps the uv rays.

thus, when the planes leave the stratosphere and return to the ground, the exterior temperature increases steadily.

its c i just checked it