A 1.0 m long metallic rod is rotated with an angular frequency of 400 rad s about an axis normal to the rod passing through its one end. The other end of the rod is in contact with a circular metallic ring. A constant and uniform magnetic field of 0.5 T parallel to the axis exists everywhere. Calculate the emf developed between the centre and the ring.

In a solenoid in vacuum of length l = 10 cm with 2052 turns per meter the current creates the field B = 70 µT. What will be the value of the current if the solenoid is placed in an external uniform magnetic field Bext = 35 µT with field lines exactly opposite to the field produced by the solenoid? Assume µo = 4Tt × 10¬7 H/m and give your answer in milli-amperes (mA).

The figure above shows a 40.0cm thin metal bar, with mass of 900g, that rests on two conducting metal supports that is connected to a battery and a 25 ohm resistor. The metal bar is placed under a uniform 0.50-T magnetic field. (a) What is the highest voltage, vmax, the battery can have without breaking the circuit at the supports?

For a solenoid in vacuum of length l = 10 cm with 10* turns per meter calculate the value of the current if the solenoid is placed in an external uniform magnetic field Bext = 35 µT with field lines exactly opposite to the field produced by the solenoid. Take vacuum permeability Ho = 4x x 10-7 H/m. Provide your answer in SI units. Answer: