A Conducting Rod Whose Length Is ℓ = 27

Multiple Choice

A conducting rod whose length is ℓ = 27.0 cm is placed on frictionless U-shaped metal rails that is connected to a lightbulb having a resistance of 5.00 Ω as shown in the figure. The rails and the rod are in the plane of the page. A constant uniform magnetic field of strength 1.20 T is applied perpendicular to and out of the paper. An external applied force moves the rod to the right with a constant speed. At what speed should the rod be pulled so that the lightbulb will consume energy at a rate of 1.10 W?

A) 2.00 m/s
B) 3.50 m/s
C) 4.26 m/s
D) 6.00 m/s
E) 7.24 m/s