Question

Define magnetic 'declination' and 'dip' at a place.

Answer 1

Magnetic Declination $\left(\theta \right)$: The angle between the magnetic meridian and geographic meridian at a place is called Magnetic Declination at that place.
Magnetic Inclination or Angle of Dip (I): It is the angle between the direction of total magnetic field of earth and a horizontal line in magnetic meridian.