Question

 In case of a bar magnet, lines of magnetic induction
(A) Start from the North pole and end at the South pole
(B) Run continuously through the bar and outside
(C) Emerge in circular paths from the middle of the bar
(D) Are produced only at the North pole like rays of light from a bulb

Answer 1

Hint:
In order to solve this question, we should know that a magnet has two poles known as the North pole and south pole, and the field around which the magnetic effect can be observed is called the magnetic field while the direction of the magnetic field is represented by lines called magnetic field lines, here we will discuss magnetic field lines direction for a bar magnet.




Complete step by step solution:
A bar magnet has two poles, the north pole and the south pole and it’s observed that magnetic field lines originate from the north pole and end in the south pole but inside the bar magnet the direction of magnetic field lines is from the south pole to north pole and hence completely these magnetic field lines form a closed loop around the bar magnet, So from the given options, we can see that only the case which is magnetic induction runs continuously through the bar and outside which means magnetic field lines are continuous meaning they are not broken anywhere in the path of closed loop and they exist outside the bar magnet.
Hence, the correct answer is option (B) Run continuously through the bar and outside


Therefore, the correct option is B.




Note:
It should be remembered that magnetic field lines always form closed loops wherever they exist, they are not like electric field lines which originate from the charge and spread in whole space and never form closed loops.