HW 6 Worked Out

# Cw as the current in the wire increases the flux is

• Notes
• 11
• 100% (1) 1 out of 1 people found this document helpful

This preview shows page 3 - 6 out of 11 pages.

CW; as the current in the wire increases the flux is increased in direction towards the plane 23.39 The figure shows a zero-resistance rod sliding to the right on two zero-resistance rails separated by the distance = 0.363 . The rails are connected by a 11.8 resistor, and the entire system is in a uniform magnetic field with a magnitude of 0.850 . Find the force that must be exerted on the rod to maintain a constant current of 0.168 in the resistor. F = B I L = 0.850 T* 0.168 A * 0.363 m = 51.8 mN What is the rate of energy dissipation in the resistor? Power: P = I 2 R = (0.168) 2 * 11.8 = 0.333 W = 0.333 W What is the mechanical power delivered to the rod? Mechanical Power: P = F * v = I 2 R = 0.333 W

Subscribe to view the full document.

= 0.333 W Motional EMF in a Conducting Rod In the figure, a conducting rod of length = 31.0 moves in a magnetic field of magnitude 0.540 directed into the plane of the figure. The rod moves with speed = 5.00 in the direction shown. When the charges in the rod are in equilibrium, which point, a or b, has an excess of positive charge? B The force on a charge moving with velocity in a magnetic field is given by . The magnitude of the force is given by where is the magnitude of the charge, and are the magnitudes of the velocity and magnetic field and is the angle measured from the direction of to the direction of . When is perpendicular to , and . You can use the right-hand rule to determine the direction in which the electrons in the rod are forced to move. What is the direction of the electric field in the rod? B A Keep in mind that the electric field exists due to the separation of the positive and negative charges caused by the magnetic force. Also, recall that electric field lines start on positive charges and end on negative charges. When the charges in the rod are in equilibrium, what is the magnitude of the electric field within the rod? E = F / q = v x B =
= 2.7 V/m Which point, a or b, has a higher potential? B What is the magnitude of the potential di ff erence between the ends of the rod? V = W / q = F L / q = E L = v B L = 5 * .54 * .31 = .837V = 0.837 V What is the magnitude of the motional emf induced in the rod?

Subscribe to view the full document.

• Spring '12
• Griffith
• Physics, Work, Magnetic Field, Faraday's law of induction, conducting rod

{[ snackBarMessage ]}

###### "Before using Course Hero my grade was at 78%. By the end of the semester my grade was at 90%. I could not have done it without all the class material I found."
— Christopher R., University of Rhode Island '15, Course Hero Intern

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern