The force on a straight current-carrying wire in a magnetic field is proportional to the current in the wire, the strength of the field, and the of the wire. a) make-up b) length c) x-section

magnetic force on a current carrying wire is given as

so it is proportional to

(i) current in the wire (i)

(ii) strength of magnetic field (B)

(iii) length of the wire (L)

so correct answer would be

B) Length

c because the action was the roller coaster reaches bottom of hill (action) reaction would be blood tends to drain away from head

hope this !