Q.1. Write three properties of magnetic field lines ?
Ans:- (i) The magnetic field line originate from the north pole of a magnet and end at its south pole.
(ii) The strength of magnetic field is indicated by the degree of closeness of the field lines.
(iii) They form closed continuous curves.
Q.2. Magnetic field lines form closed loop whereas electric field lines does not closed loop why ?
Ans:- Electric field lines originate from the positive charges and terminate on negative charges. If the electric field line form closed loops, these line must originate and terminate on the same which is not possible.Magnetic lines form continuous closed loops because magnetic monopole does not exist in nature.
Q.3. What is magnetic Meridian ?
Ans:- A continuous line on the earth’s surface connecting the north and south magnetic poles.
Q.4. What is dip Angle ‘OR’ Angle of inclination ?
Ans:- The angle made by total Earth magnetic field in the magnetic meridian with the horizontal direction is called as dip angle OR Angle of inclination.
Tanδ= Magnetic field vertical /Magnetic field horizontal
Q.5. What is angle of declination ?
Ans:- The angle between the geographical meridian and magnetic meridian is called angle of declination
Q.6. How many types of magnetic substance ?
Ans:- There are three types of magnetic substance. (i) Diamagnetic (ii) Paramagnetic (iii) Ferromagnetic .
Q.7. Write two differences between diamagnetic , paramagnetic and Ferromagnetic ?
Ans:- Diamagnetic- (i) Very less magnetised opposite to the direction magnetic field
(ii) Gold , Silver , Water , Zinc , Alcohol , Lead e.t.c. are Diamagnetic.
Paramagnetic- (i) Very less magnetised in the direction of magnetic field.
(ii) Al , Cr , Mn , Mg , Na , K e.t.c. are Paramagnetic.
Ferromagnetic- (i) Very high magnetised in the direction of magnetic field.
(ii) Fe , Co , Ni are Ferromagnetic.