. A very long solenoid has a density of coils n turns per unit length. We apply a current I through the solenoid. Use Biot-Savart law to derive the magnetic field in the center of the the solenoid. Verify that it agrees with the result from the Ampere’s law. You can approximate the solenoid as infinitely long.

Aray of light traveling parallel to the principal axis of a concave mirror will be reflected through the mirror's

Imagine you had to physically add electrons, one at a time, to a previously neutral conductor. you add one electron very easily, but the second electron requires more work. in your initial post to the discussion, explain why this is. also, what happens to the work needed to add the third, fourth, fifth, and subsequent electrons

Apulley system is used to lift a 2,000 newton engine up a distance of 3 meters. the operator must apply a force of 250 newtons to the chain of the pulley system to lift the motor. to lift the engine 3 meters, the operator must pull a total of 30 meters of chain through the pulley system. what is the value of di?