Question

In a straight solenoid magnetic field is half at the end why

Answer 1

Because at the centre magnetic field is zero and at the end magnetic field is maximum so magnetic field is half at the end in a straight solenoid

hope u understand

Answer 2

annyeongHaseyo... :)

It becomes half because the magnetic field strength on the axis going right through the solenoid, in the place on the end of the solenoid is then the field of an infinitely long solenoid minus half of it because half is missing, and so the field strength is half as big on the ends (but right in the middle).