A horizontal wire of length 40 cm carries a current of 1.5 A. Around the wire is a magnetic field of strength 8×10−2 T at right angles to the direction of the current. The wire is suspended in mid-air. Taking g=9.81 Nkg−1 , the best estimate of the mass of the wire is
a. 3.3×10−3 kg.
b. 4.9×10−3 kg.
c. 8.2×10−3 kg.
d. 12.3×10−3 kg.