GURE 4 shows the magnetic field is constant and is directed into e plane of the drawing. If the bar is sliding to the right, explain on w to use Lenz's law to find the direction of the induced current. L x B Closed path FIGURE 4

You pull a bar magnet out of coil of wire. What are the directions of the induced current and magnetic field? Draw a sketch of the situation, noting whether your answer would change if the magnet’s south pole left the wire instead of the north pole.

A long straight wire is fixed in space and has current I. Draw the wire vertically with the current flowing upward. A square wire loop with side length s and resistance R is in the plane of the page and has its closest side a distance x away from the wire. Find the magnetic flux through the square HINT: The B-field depends on distance from the wire so you will have to integrate. The loop is pushed with velocity v toward the Find the rate of change of magnetic flux. HINT: Don't forget the chain rule. If f(x(t)) is a function of x and x is a function of t, then df/dt = (df/dx)(dx/dt) Find the current induced in the square Which direction is the current flowing? Explain with Lenz's Law Find the net magnetic force on the

Equilateral with side length perpendicular to the vertices of the triangle, the plane of the figure I1 and I2 = I3 currents from long straight wires insertedpass. The triangle of these currents now the contributions to the net area, B1, B2, and B3 on the figure shows the total magnetic direction and intensity Find. Express your answer in terms of what is given. The directions of the currents are shown on the figure.