The distance of two points on the axis of a magnet from its centre is $10 \,cm$ and $20 \,cm$ respectively. The ratio of magnetic intensity at these points is $12.5 : 1. $ The length of the magnet will be......$cm$
The distance of two points on the axis of a magnet from its centre is $10 \,cm$ and $20 \,cm$ respectively. The ratio of magnetic intensity at these points is $12.5 : 1. $ The length of the magnet will be......$cm$
- A
$5 $
- B
$25$
- C
$10$
- D
$20 $
Similar Questions
If a magnet of pole strength $m$ is divided into four parts such that the length and width of each part is half that of initial one, then the pole strength of each part will be
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- [IIT 2002]
$(a)$ What happens if a bar magnet is cut into two pieces: $(i)$ transverse to its length, $(ii)$ along its length?
$(b)$ A magnetised needle in a uniform magnetic field experiences a torque but no net force. An iron nail near a bar magnet, however, experiences a force of attraction in addition to a torque. Why?
$(c)$ Must every magnetic configuration have a north pole and a south pole? What about the field due to a toroid?
$(d)$ Two identical looking iron bars $A$ and $B$ are given, one of which is definitely known to be magnetised. (We do not know which one.) How would one ascertain whether or not both are magnetised? If only one is magnetised, how does one ascertain which one? [Use nothing else but the bars $A$ and $B$.]
$(a)$ What happens if a bar magnet is cut into two pieces: $(i)$ transverse to its length, $(ii)$ along its length?
$(b)$ A magnetised needle in a uniform magnetic field experiences a torque but no net force. An iron nail near a bar magnet, however, experiences a force of attraction in addition to a torque. Why?
$(c)$ Must every magnetic configuration have a north pole and a south pole? What about the field due to a toroid?
$(d)$ Two identical looking iron bars $A$ and $B$ are given, one of which is definitely known to be magnetised. (We do not know which one.) How would one ascertain whether or not both are magnetised? If only one is magnetised, how does one ascertain which one? [Use nothing else but the bars $A$ and $B$.]