circuit

For each of the following circuits, determine how the brightness of the bulbs change when the switch is closed. Please see attachment

Physics III Problem

A 10 mF capacitor is placed in a series circuit with a 100 Kohm resistor, a switch, and a 10V battery. a. What is the RC time constant in s? b. What is the initial current when the switch is closed in mA? c. What is the charge on the capacitor at t=RC in C? d. What is the voltage drop across the resistor when t=RC in A?

power lines and magnetic fields

A power line is 3.5m off the ground and is carrying 75 amps. A man standing under the power line is holding a compass 1.25m off the ground. 1) how large is the magnetic field produced on the compass by the power line? 2) if the power line runs east and west, how does its magnetic field affect the direction in which the compass points? 3) if the power line runs north-south, how does the magnitic field affect the direction in which the compass points?

Algebra/Physics

A power line is 3.5m off the ground and is carrying 75 amps. A man standing under the power line is holding a compass 1.25m off the ground. 1) how large is the magnetic field produced on the compass by the power line? 2) if the power line runs east and west, how does its magnetic field affect the direction in which the compass points? 3) if the power line runs north-south, how does the magnitic field affect the direction in which the compass points?

Algebra/Physics

A 5 meter long copper wire, with a cross sectional area of 1.0mm^2 is bent into a circle. This loop of wire is mounted in a vertical plane between the poles of a magnet. This magnet is aligned so that its field points in a horizontal direction from the west to the east; the magnitude of this field is 7.25*10^(-4)T. The loop of wire is then spun at an angular rate of 10pi radians/sec about a vertical axis running through the center of the loop. 1) what emf is induced? 2) what current is induced in the wire?