Lightning bolts can carry currents up to approximately 20 kA. We can model such a current as the equivalent of a very long, straight wire. For related problem-solving tips and strategies, you may want to view a Video Tutor Solution of Magnetic field of a single wire. Part A If you were unfortunate enough to be 4.5 m away from such a lightning bolt, how large a magnetic field would you experience? Express your answer in teslas. Submit Request Answer Part B How does this field (B1) compare to one (B2) you would experience by being 4.5 cm from a long, straight household current of 10 A?
Two long, straight, parallel wires, 10.0 cm apart carry equal 4.00-A currents in the same direction, as shown in (Figure 1). Figure 1 of 1 Part A Find the magnitude of the magnetic field at point P1, midway between the wires. Express your answer in teslas. Submit Request Answer Part B What is its direction? to the left to the right upward downward no field Part C Find the magnitude of the magnetic field at point P2, 25.0 cm to the right of P1. Express your answer in teslas. Submit Request Answer Part D What is its direction? to the left to the right upward downward no field Part E Find the magnitude of the magnetic field at point P3, 20.0 cm directly above P1. Express your answer in teslas. Submit Request Answer Part F What is its direction? to the left to the right upward downward no field
A long, horizontal wire AB rests on the surface of a table and carries a current I. Horizontal wire CD is vertically above wire AB and is free to slide up and down on the two vertical metal guides C and D (the figure (Figure 1)). Wire CD is connected through the sliding contacts to another wire that also carries a current I, opposite in direction to the current in wire AB. The mass per unit length of the wire CD is λ. Figure 1 of 1 Part A To what equilibrium height h will the wire CD rise, assuming that the magnetic force on it is due entirely to the current in the wire AB ? Express your answer in terms I, λ, magnetic constant μ0, and acceleration due to gravity g. h = Submit Request Answer
Part A Calculate the magnitude of the magnetic field at point P due to the current in the semicircular section of wire shown in the figure (Figure 1). (Hint: Does the current in the long, straight section of the wire produce any field at P ? ) Express your answer in terms of the variables I, R, and magnetic constant μ0. Submit Request Answer Part B Find the direction of the magnetic field at point P. into the page out of the page Figure 1 of 1
A closely wound, circular coil with radius 2.80 cm has 780 turns. Part A What must the current in the coil be if the magnetic field at the center of the coil is 0.0790 T ? Express your answer with the appropriate units. Submit Request Answer Part B At what distance x from the center of the coil, on the axis of the coil, is the magnetic field half its value at the center? Express your answer with the appropriate units.
Coaxial Cable. A solid conductor with radius a is supported by insulating disks on the axis of a conducting tube with inner radius b and outer radius c in the following figure. The central conductor and tube carry equal currents I in opposite directions. The currents are distributed uniformly over the cross sections of each conductor. (Figure 1) Figure 1 of 1 Part A Derive an expression for the magnitude of the magnetic field at points outside the central, solid conductor but inside the tube ( a < r < b ). Express your answer in terms of the variables I, r, and magnetic constant μ0. Submit Request Answer Part B Derive an expression for the magnitude of the magnetic field at points outside the tube (r > c). Express your answer in terms of the variables I, r, and magnetic constant μ0.
Two long, parallel wires hang by 4.00−cm−long cords from a common axis (see the figure (Figure 1)). The wires have a mass per unit length of 1.55×10−2 kg/m and carry the same current in opposite directions. Figure 1 of 1 Part A What is the current in each wire if the cords hang at an angle of 6.00∘ with the vertical? Express your answer in amperes. Submit Request Answer
In the wire shown in (Figure 1) segment BC is an arc of a circle with radius 30.0 cm, and point P is at the center of curvature of the arc. Segment DA is an arc of a circle with radius 20.0 cm, and point P is at its center of curvature. Segments CD and AB are straight lines of length 10.0 cm each. Part A Calculate the magnitude of the magnetic field at a point P due to a current 12.0 A in the wire. Express your answer with the appropriate units. Submit Request Answer Part B Figure 1 of 1 What is the direction of magnetic field? into the page out of the page Submit Request Answer
A long, straight wire with a circular cross section of radius R carries a current I. Assume that the current density is not constant across the cross section of the wire, but rather varies as J = αr, where α is a constant. Part A By the requirement that J integrated over the cross section of the wire gives the total current I, calculate the constant α in terms of I and R. Express your answer in terms of the variables I and R. Part B Use Ampere's law to calculate the magnetic field B(r) for r ≤ R. Express your answers in terms of I. Express your answer in terms of the variables I, R, r, and magnetic constant μ0. Submit Request Answer Part C Use Ampere's law to calculate the magnetic field B(r) for r ≥ R. Express your answers in terms of I. Express your answer in terms of the variables I, r, and magnetic constant μ0.
The long, straight wire AB shown in (Figure 1) carries a current of 14.0 A. The rectangular loop whose long edges are parallel to the wire carries a current of 5.00 A. Part A Find the magnitude of the net force exerted on the loop by the magnetic field of the wire. Express your answer in newtons. Submit Request Answer Part B Find the direction of the net force exerted on the loop by the magnetic field of the wire. to the left to the right upward downward Submit Request Answer