1. The problem statement, all variables and given/known data calculate a value for B at a distance of 50cm, in ,air, from a long straight cable carrying a current of 1000A. 2. Relevant equations F=Bqv=BIl I=q\t = qv/l F=LIB 3. The attempt at a solution i have not been able to calculate an answer as there are constantly two unknowns and i am unable o fine F.