Define magnetic flux density. Also write its formula.

Choose the incorrect statement from the following regarding magnetic lines of field

Identify the poles of the magnet given in the figure.

If the key in the arrangement (figure) is taken out (the circuit is made open) and magnetic field lines are drawn over the horizontal plane $ABCD$, the lines are

What is the direction of magnetic field lines outside a bar magnet?

Identify the poles of the magnet in the given figures ($1$) and ($2$).

Figure $\left(1\right)$

  
 Figure $\left(2\right)$                                                                                                                                                                                        

Answer the following questions :

(i) What is the direction of magnetic field lines outside a bar magnet?

(ii) What is SI unit of magnetic field?

(iii) What does crowding of magnetic field lines indicate?

(iv) What is the frequency of A.C. in India?

(v) Name two organs in the human body where magnetic field is quite significant.