Download 7 Questions with Solutions in College Physics II - Midterm Exam | PHYS 135B and more Exams Physics in PDF only on Docsity!
Phys 135B: College Physics II Midterm 2 Solutions Be neat and show all work to get full credit 1 - What is the current in amperes if 1200 Na+^ ions flow across a cell membrane in 3.5 μs? The charge on the sodium is the same as on an electron, but positive. 2 - ) A hair dryer draws 7.5 A when plugged into a 120-V line. ( a ) What is its resistance? ( b ) How much charge passes through it in 15 min? (Assume direct current.) (a). (b) 3 - (a) In the circuit below, if the load resistor is 1 Ω, what terminal voltage will the battery provide? . (b) In the circuit below, find the equivalent resistance between points A and B. 4 - A heater coil connected to a 240-Vrms ac line has a resistance of 34 Ω ( a ) What is the peak current? (b) What is the average power used? (c) What are the maximum and minimum values of the instantaneous power? (a) (b) (c) (or 5 - A rectangular solid made of carbon (ρ = 1.68x10-^8 Ω-m ) has sides of lengths 2.0 cm, 3.0 cm, and 8. cm, lying along the x, y , and z axes, respectively, as shown. If a current will flow along the y direction , determine the resistance it will encounter.
6 - The charged particles move in the vicinity of a current-carrying wire as shown below. For each charged particle, the arrow indicates the direction of motion of the particle, and the +^ or^ − indicates the sign of the charge. For each of the particles, indicate the direction of the magnetic force due to the magnetic field produced by the wire. Downward Downward To the right No force!
7 - A straight stream of protons passes a given point in space at a rate of 1.^510 protonss.
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× What magnetic
field do they produce 2.0 m from the beam? 8 - A thin 12-cm-long solenoid has a total of 420 turns of wire and carries a current of 2.0 A in the direction shown. (a) Calculate the field inside near the center, and (b) indicate its direction. (a) (b) To the left! 9 - A current-carrying wire with 3-Amp is placed in a magnetic field of strength 0.5 T, and whose direction is into the page. If the wire is in the plane of the page, (a) what is the direction of the force it will feel? (b) What is its magnitude per unit length? (a) To the right! (b) 10 - What is the direction of the induced current in the circular loop due to the current shown in each part of the figure below? Note: the thick arrow indicates the movement direction! (a) Loop is pulled out. CW (b) Both the wire and the loop are stationary CW (c) The magnet is pulled upward CCW (d) The magnet is pushed toward the loop from side No current!
