Which of the following choices of path allow you to use ampère's law to find vector b(r)?
a) the path must pass through the point r .
b) the path must have enough symmetry so that b(r)*dl is constant along large parts of it.
c) the path must be a circle.

Acylindrical specimen of a nickel alloy having an elastic modulus of 207 gpa (30 × 106psi) and an original diameter of 10.2 mm (0.40 in.) experiences only elastic deformation when a tensile load of 8900 n (2000 lbf) is applied. compute the maximum length of the specimen before deformation if the maximum allowable elongation is 0.25 mm (0.010 in.)

The two required components for a generator are

For which pair of objects would adding the same a