1. A lovely way to shield against the Earth's magnetic field was used in a monopole experiment at Stanford University. A deflated lead-foil balloon is cooled below its critical temperature. Inflating the balloon then provides a field-free region inside of its hollow. How does it work?
2. A flat cirular coil having a diameter of 25 cm is to produce a B-field at its center of 1.00mT. If it has 100 turns, how much current must be provided to it?
3. A thousand turns of fine wire are wrapped around a thin hollow cardboard core, making a 100-Ohm coil 20.0 cm long and 2.00 cm in diameter. What B-field will exist inside the coil at its center when placed across a 20.0-V dc source?
4. Suppose we remove the magnetic deflection yoke from the neck of a TV picture tube so that teh electron beam travles straight down the central axis. For the brightness level given, there are 6.0 x 10^12 electrons at the screen per second. Determine the magnetic field (magnitude and direction) caused by the beam at a radial distance of 1.5 cm from it.
5. A straight wire is positioned in a uniform magnetic field so that the force on it 4.00 N is a maximum. If the wire is 20 cm long and carries 10.0 A, what is the magnitude of the B-field?
6. When 2.00 A passes along a 3.00-m length of straigth wire that is entirely immersed in a uniform B-field, it experiences a maximum force of 6.00 x 10^-3 N. How strong is the field?
Magnetism questions are solved.