A straight wire of length 30 cm and mass 60 mg lies in a direction `30^(@)` east of north.The earth's magnetic field at this is horizontal and has a magnitude of 0.8 G.What current must bre passed through the wire,so that it may float in air ?

A straight wire of mass 400 g and length 2m carries a current of 2A. It is suspended in mid air by a uniform horizontal field B. What is the magnitude of the magnetic field ?

A straight wire of mass 400 g and length 2m carries a current of 2A. It is suspended in mid air by a uniform horizontal field B. What is the magnitude of the magnetic field ?

A telephonic cable at a place has four long straight horizontal wires carrying a current of 1.0amp. in the same direction east to west. The earth's magnetic field at the place is 0.39G and the angle of dip is 35^@ . The magnetic declination is almost zero. What are the resultant magnetic fields at points 4.0cm below and above the cable?

A loop of flexible conducting wire of length l lies in magnetic field B which is normal to the plane of loop. A current l is passed through the loop. The tension developed in the wire to open up is

A long straight wire is bent as shown below. Find the resultant magnetic field B at the centre C of the circular path of radius 2 cm if a current I of 5A is passed through the wire.

A conducting rod of 1 m length and 1 kg mass is suspended by two verticle wires through its ends. An external magnetic field of 2T is applied normal to the rod. Now the current to be passed through the rod so as to make the tension in the wire zero is [Take g = 10 ms^(-2)]

A straight wire of mass 200 g and length 1.5 m carries a current of 2 A. It is suspended in mid-air by a uniform horizontal magnetic field B. What is the magnitude of the magnetic field?

A straight wire of mass 200 g and length 1.5 m carries a current of 2 A. It is suspended in mid-air by a uniform horizontal magnetic field B. What is the magnitude of the magnetic field?

A straight wire of mass 200 g and length 1.5 m carries a current of 2 A. It is suspended in mid-air by a uniform horizontal magnetic field B. What is the magnitude of the magnetic field?

A wire of 60 cm length and mass 16 gm is suspended by a pair of flexible leads in a magnetic field of induction 0.40 T. What are the magnitude and direction of the current required to remove the tension in the supporting leads?