question_answer 20)

A straight horizontal conducting rod of length 0.45 m and mass 60 g is suspended by two vertical wires at its ends. A current of 5.0 A is set up in the rod through the wire.                 (a) What magnetic field should be set up normal to the conductor in order that the tension in the wires is zero?                 (b) What will be the total tension in the Hires if the direction of current is reversed keeping the magnetic field same as before? (Ignore the mass of the wires.) .  

Answer:

(a) Here                 i.e.                                                (b) In case current is reversed, the tension                 weight of rod