Question

#4

TEST 2, PHYS 1442. Instructor: Dr. G. Kolmakov Student Name Date: 5/1/2018 Notes: 1. Show equations you use and show your work. Answers without work shown will not be given any credit. 2. Box the final answers. 3. Show units in the answers. 4. Maximum point for the test is 100. 1. (10 points) What is the resistance of a 35-meter long wire that has a diameter of 0.812*10- m and is made of copper? The resistivity of copper is 1.68*10-8 Ω m. 2. (15 points). A 9.0-Volt battery is connected to the circuit shown in the associated picture. How much power is dissipated in the circuit? 3. (I5 points) Alpha particles of charge +3.2x10-19 Coulombs and mass 6.6x10-2 (1S poims) Alpha particles of charge +3.2x101" Coulombs and mass 6.6x10W kilograms are emitted from a radioactive source at a speed of 1.6x10" meters per For problem second. What magnetie field strength would be required to bend them into a circular path of a radius of 0.18 meters? 4. (U5 points) A circular conducting ring of radius R-0.3 m is connected to two exterior straight wires at two ends of a diameter, as is shown in the associated figure. The current 1-25 A splits into unequal portions (as shown) while passing through the ring. What is the magnetic field strength at the center of the ring? 0.351 5. (IS points). Three current-carrying wires with a length of 0.75 m each are placed in the plane of the page parallel to each other. The distances between the wires are given in the figure. The currents running in the wires are all equal to 1- 150 A, the directions of the currents are marked in the figure by arrows. Find the absolute value and the direction of the magnetic force acting on the leftmost wire. For problem 4 6. (15 poins) The magnetic flux through each loop of a 75-lop coil is given by (8.8t 0.51t2) x 10-2 T m2, where time r is in seconds. What is the induced voltage in the coil at r-3.0 sec? .(J5 points) Determine the magnitudes of the currents through R and R V1 -9.0V R 22 32 For problem S R 18 2 For problem7 Bonus question 8.(10 points) A circular loop of wire, of radius r-0.5m, carries current 1-130 A. It is placed in a magnetic field whose straight lines seem to diverge from a point a distance d-1.4 m below the ring on its axes (That is, the field makes an angle 6with the loop at all points, as is shown in the figure, where tan(o)-rid.) Determine the magnetic force on the loop.

Answer 1

ん 25A. 2 R 2 R 2 R 子 2 0.3 or, B= 1.570 796 x10"