Electric field

If an electron enter a uniform magnet field having a flux density 200uT at a speed of 2x10 6 ms-1 perpendicular to the field. Determine the radius of its orbit, then find the required electric field strength, applied perpendicular to the magnetic field, if the electron is to be continue in a straight line on entering the combined fields, and sketch it?

Electric potential due to rotating blade in a magnetic field

1.A helicopter has blades of length 3.0m, rotating at 2.0rev/s about a central hub. If the vertical component of Earth's magnetic field is 5.0*10^-5T, what is the emf induced between the blade tip and the central hub? 2.A bolt of lightning depicted in a picture passes 200m from a 100-turn coil oriented as shown. If the current in the lighting bolt falls from 6.02*10^6A to zero in 10.5us, what is the average voltage induced in the coil? Assume that the distance to the center of the coil determines the average magnetic field at the coil's position. Treat the lighting bolt as a long, vertical wire. Here is the answer just need to know how to get it. ANSWER=115kV 3.An important news a... click for more

Finding charges: Given the total charge only

Each of two small spheres is charged positively, the combined charge being 5 x 10^-5 C. If each sphere is repelled from the other by a force of one newton, when the spheres are two meters apart, how is the total charge distributed between the two spheres ?

Electric potential induced in a rotating rod.

A rod of length l is pivoted at one end rotates with uniform angular velocity w in a uniform magnetic field of intensity B. The magnetic fluxes are perpendicular to the plane of rotation of rod. Calculate the induced EMF across the two ends of rod.

X-ray production

X-ray production: dependence of wavelength and intensity on various parameters. Tips to remember.