Q: Define magnetic declination.
A: At a given place, the angle between geographical meridian and magnetic meridian of Earth is defined as magnetic declination.
Q: Define magnetic inclination (or) angle of dip.
A: The magnetic inclination (or) angle of dip at a place is defined as the angle made by the direction of Earth's magnetic field with the horizontal direction in magnetic meridian.
Q: Classify the following materials with regard to magnetism.
(i) Manganese (ii) Cobalt
(iii) Nickel (iv) Bismuth
(v) Oxygen (vi) Copper
A: Manganese & Oxygen are Paramagnetic materials. Cobalt & Nickel are Ferromagnetic materials. Bismuth & Copper are Diamagnetic materials.
Q: Magnetic lines form continuous closed loops. Why?
A: Isolated (mono) magnetic poles do not exist, so magnetic lines form continuous closed loops.
Q: What happens to compass needles at the Earth's poles?
A: Compass needles does not work at magnetic poles of the Earth, because at poles horizontal component of Earth's magnetic field (BH) is zero.
Some more important questions:
Q: What is the magnetic moment associated with a solenoid?
Q: If the number of turns of a solenoid is doubled, keeping the other factors constant, how does the magnetic field induction at the axis of solenoid change?
Q: If B is the magnetic field produced at centre of a circular coil of one turn of length 'L' carrying
a current i, then what is the magnetic induction at centre of the same coil which is made into 10 turns?
Q: What are the SI units of Magnetic moment, Magnetic induction and Magnetic field?