Q1: Pick up the correct statement from the following :

ANS:D - all the above.

1. "The horizontal angle between the magnetic meridian and true meridian at a place is called magnetic declination or variance of the compass." This statement refers to magnetic declination, which is the angle between magnetic north and true north at a specific location on the Earth's surface. It indicates the difference between the direction indicated by a magnetic compass and the direction of true north.
2. "The imaginary lines which pass through points at which the magnetic declinations are equal at a given time are called isogonic lines." Isogonic lines are lines on the Earth's surface that connect points where the magnetic declination is the same. These lines help illustrate the variation in magnetic declination across different geographic regions.
3. "The isogonic lines through places at which the declination is zero are termed agonic lines." Agonic lines are a specific type of isogonic line where the magnetic declination is zero. This means that the magnetic north and true north align at points along the agonic line, making it an important reference for navigation and cartography.