5. A long cylindrical conductor of radius R carries a current I. The current density is non- uniform, and is a function of the radius according to J = br, where b is a constant. Find an expression for the magnetic field for both rR (i.e. inside and outside the conductor). Assume that R is measured from the center of the conductor.

An electron moves in a straight line at speed 250 m/s along the positive y-axis through uniform electric and magnetic fields. The magnetic field is directed into the page and has magnitude 2 T. Neglect gravity. The mass of the electron is 9.1 x 10³1 kg. a. What is the electric field (specify both magnitude and direction)? b. Now imagine the electric field has been turned off. What will be the radius of the electron's subsequent path?

. A uniform electric field E and a uniform magnetic field B are present in some region. A particle with positive charge q and mass m moves with speed v to the right. a. What do the directions of the electric field and magnetic field need to be in order for the particle to move with constant speed? Ignore gravity, air resistance and any other non-electromagnetic forces. b. Find the ratio E/B in order for the particle to move at constant speed.

Magnetic field is given in units of Tesla (T). 1. Straight forward What is the strength of the magnetic field 2.00 mm from a straight wire carrying 10 A of current?

A 0.55-meter-long wire carries a current with electron flow directed to the East. It is present in a magnetic field of intensity of 0.050 T and directed to the South. The force acting on the wire is 0.220 N. a. What is the magnitude of the current in the wire? b. In what direction is the force acting on the wire?

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1. A magnetic field has a magnitude of 1.20 x 10 T, and an electric field has a magnitude of 4.70 x 10° N/C. Both fields point in the same direction. A positive 2.5 µC charge moves at a speed of 3.00 x 10° m/s in a direction that is perpendicular to both fields. Determine the magnitude of the net force that acts on the charge. N

An electron has an initial velocity of (11.2 + 16.8 k) km/s, and a constant acceleration of (1.63 x 1012 m/s²) in the positive x direction in a region in which uniform electric and magnetic fields are present. If B = (365 µT)i find the electric field E. i î+ i ! j+ i !nkts N/C or V/m

a.) A wire 4 m long has a mass of 224 g. The wire is connected to an emf. What is the minimum current in the wire that would allow it to levitate above the ground in a magnetic field of magnitude0.4 T? Round your answer to 2 decimal places b.) Per previous question, what direction must the current flow?

Magnetic and electric field lines are in many ways similar, with few crucial differences. Which of the properties listed below does NOT apply to both fields? O All of these properties apply to both E and B field lines. The density of lines is proportional to the field strength in that area. Field lines never intersect. Tangent to the line at a point gives you the direction of the field as that point. O Field lines form closed loops.