A magnet is moving toward a solenoid and a potential difference is induced between the two ends of the solenoid wire. Draw the induced magnetic field direction and the induced current direction, on a side view, as seen from the magnet side under the following conditions: a. The speed of the magnet is increased. b. The magnet is pulled back away from the solenoid. c. The magnet is stopped, and the solenoid moves away from the magnet.

1. Recall the induction example from lecture in which a resistanceless metal bar with length & slides to the right on metal rails with a constant speed v and the metal rails are connected to a resistor R. The entire system is placed in a uniform constant magnetic field with magnitude B pointing out of the screen. е R a) Use Lenz's last to determine the direction in which the induced current flows. b) In lecture we simply assumed the bar moves with constant speed v. Show that an external force is needed to ensure the bar travels right with constant speed and determine the magnitude of this force (Hint: there will be a magnetic force on the bar due to the current flowing through it). c*) Show that the power dissipated in the resistor equals the rate at which work is done on the bar by the external force.

A bar magnet is let fall toward the center of a conducting loop of wire, with the north pole oriented downward. Viewed from the same side of the loop as the magnet, as the north pole approaches the loop, what is the direction of the induced current? Parallel to the length of the magnet. Counterclockwise Clockwise zero

4. Inductance of a long solenoid: A long thin solenoid has N turns, a length W, area A and a current I. a. What is the magnetic flux through one turn of the solenoid? 6 per turn = BA= b. Determine the inductance L of the solenoid. LI= NO. per turn c. A very long solenoid has 500 turns, a radius of 2 cm and a length of 40 cm and a current of 3A. What is the inductance of the solenoid? d. The coil in an inductor is usually wrapped around an iron core which amplifies the magnetic field. Assume the iron core makes the magnetic field 700 times larger than without the core. What is the inductance of the solenoid in (c) with the iron core? 600 # 212 RCE

The magnetic field at the center of a solenoid L = 75 cm long is B = 0.11 T when a current of I = 3.5 A flows through the solenoid wire.   1. Solve the formula for the magnetic field near the center of a long, tightly wound solenoid for the number of turns, N, in the solenoid. The expression should be in terms of the given variables.  2.  Calculate the value of the number of turns, N.

A solenoid sits in front of you and you are facing one end. You move the south end of a bar magnet further away from the end of the solenoid that you are facing. What will the direction of the induced current in the solenoid be as you move the bar magnet further from the solenoid (from your perspective)? clockwise counter-clockwise

Question 1: #65       The 10-cm-wide, zero-resistance wire shown in Figure below, is pushed toward the 2.0 Ω resistor at a steady speed of 0.50 m/s.  The magnetic field strength is 0.50 T. a. What is the magnitude of the pushing force? b. How much power does the pushing force supply to the wire? c. What are the direction and magnitude of the induced current? d. How much power is dissipated in the resistor?

6. For each situation, circle the best choice. a. A current carrying wire is pulled away from a conducting loop as shown. Which way will an induced current flow in the conducting loop? I- Clockwise in the loop, Counterclockwise in the loop, There is no induced current, More information is needed b. A metal bar completes a circuit as in moving upwards in a magnetic field as drawn. Which way will an induced current flow in the loop? Clockwise in the loop, Counterclockwise in the loop, There is no induced current, More information is needed

Two high-current transmission lines carry currents of 45 A and 78 A in the same direction and are suspended parallel to each other 28 cm apart. If the vertical posts supporting these wires divide the lines into straight 16 m segments, what magnetic force does each segment exert on the other? _N. Exponential format with 2 SẺ. QUESTION 14 An induced emf will occur if A. the strength of the magnetic field is changed. B. the coil's area is changed. C. the angle at which the magnetic field and the coil's area meet is changed. D. all of the above.

What is the radius of a tightly wound solenoid of circular cross-section that has 170 tusifa change in its internal magnetic field of 40T/s causes a 70 A current to flow/ The restance of the circuit that contains the solenoid is 150. The only emf source for the circuit is the induced eml. a) 0.22 m b) 0.059 m c) 0.015 m d) 0.79 m