The figure shows two closed paths wrapped around two conducting loops carrying currents i = 7.9 A and i2 = 3.0 A. What is the value of the integral B. ds for (a) path 1 and (b) path 2? (a) Number i Units (b) Number i Units DI D2 A solenoid that is 114 cm long has a radius of 1.53 cm and a winding of 1320 turns; it carries a current of 3.62 A. Calculate the magnitude of the magnetic field inside the solenoid. Number i Units A student makes a short electromagnet by winding 390 turns of wire around a wooden cylinder of diameter d = 2.5 cm. The coil is connected to a battery producing a current of 3.3 A in the wire. (a) What is the magnitude of the magnetic dipole moment of this device? (b) At what axial distance z>>d will the magnetic field have the magnitude 4.1 T (approximately one-tenth that of Earth's magnetic field)? (a) Number i Units (b) Number i Units In the figure, four long straight wires are perpendicular to the page, and their cross sections form a square of edge length a = 26 cm. The currents are out of the page in wires 1 and 4 and into the page in wires 2 and 3, and each wire carries 16 A. What is the magnitude of the net magnetic field at the square's center? Number ! Units In the figure, four long straight wires are perpendicular to the page, and their cross sections form a square of edge length a = 12.5 cm. Each wire carries 4.00 A, and the currents are out of the page in wires 1 and 4 and into the page in wires 2 and 3. In unit-vector notation, what is the net magnetic force per meter of wire length on wire 4? Number i Units The figure shows a cross section across a long cylindrical conductor of radius a = 1.70 cm carrying uniform current 44.4 A. What is the magnitude of the current's magnetic field at radial distance (a) 0, (b) 1.31 cm, (c) 1.70 cm (wire's surface), (d)2.81 cm? (a) Number i Units (b) Number i Units (c) Number i Units (d) Number i Units