Magnetic declination or magnetic variation is the angle on the horizontal plane between magnetic north and true north.
Important Questions on Electricity and Magnetism
Assertion : The colourful curtain of green and pink lights in the sky, (which is called "Aurora Borealis") are seen in the polar regions like Alaska and North Canada, but it is not seen in India.
Reason : The earth's magnetic field lines come closer to each other at the magnetic poles, so the charge's density of the charges ejected from the sun, increases near the magnetic poles.
Assertion: The geographic north-pole does not coincide with the magnetic north pole.
Reason: The axis of the hypothetical dipole inside the earth is tilted by approximately with respect to the axis of rotation of the earth.
Assertion: The magnetic poles of earth do not coincide with the geographic poles.
Reason: The discrepancy between the orientation of a compass and true north-south direction is known as magnetic declination.
