A piece of wire is bent to form a circle with radius.It has a steady current flowing through it in a counterclockwise direction as seen from thetop (looking in the negative direction).  

What is , the z component of at the center (i.e., ) of the loop?

Express your answer in terms of,,and constants like and .

One end of a cord is fixed and a small 0.500kg object is attached to the other end, where it swings in a section of a vertical circle of radius 2.00 m, when theta is 20, the speed of the object is 8m/s. At this instant, find the tension in the string and the tangential and radial components of acceleration.

A cable exerts a constant upward tension of magnitude on a elevator as it rises through a vertical distance of . (a) Find the work done by the tension force on the elevator. (b) Find the work done by the force of gravity on the elevator.

Why do we need to put a capacitor in a circuit? Explain your answer.

In what region of space is the potential due to a uniformly charged sphere the same as that of a point charge? In what region does it differ from that of a point charge?

How would the position of Fermi level EF with respect to the intrinsic energy level Ei change, if instead of Boltzmann statistics, Fermi-Dirac statistics were used?