At a distance of 2.5 cm from a long straight current-carrying wire, the magnetic field has a value of 1.3 T. What would be the value of the magnetic field at a point that is twice as far from the wire, when the wire carries twice as much current

The magnetic field is  

Explanation:

From the question we are told that

   The distance from the wire is  d = 2.5 cm  =  0.25 m

    The magnetic field is B  =  1.3 T

Generally the magnetic field that is as a result of as current carrying conductor is mathematically represented as

so  

given that the distance and the current is doubled

=>      

Hence  

=>      

i will answer your question if you answer mine