Phy 213: General Physics III 1/14/2019Chapter 26 Worksheet 1Ohm’s Law & Electrical Circuits:1. Electric Current flows through the followingnetwork:a. What is the magnitude and direction ofthe current, i?b. How many coulombs of charge flow in 2.0min, for constant i?c. How many electrons flow in 2.0 min, forconstant i?2. Electric Current flows through the followingnetwork:a. What is the magnitude and direction of thecurrent, i?b. How many coulombs of charge flow in 5.0min, for constant i?c. How many electrons flow in 5.0 min, forconstant i?3. Starting at to= 0s, a wire conducts a time-changing current, i(t) of the form: t-maxi(t) = i et, where imax=5.0 A and =0.5 s. The resistance in the wire is 5 a. How much charge, in coulombs, will flow along the wire in 1.5 s?b. How many electrons flow along the wire in 1.5 s?c. What is the equation for the voltage as a function of time across this wire?4A3A3A3A2Ai1A3A1Ai2A3A1APhy 213: General Physics III 1/14/2019Chapter 26 Worksheet 24. A resistor has cylindrical geometry, with a resistivity = 3.5 x 10-5 .m at 20oC and temperature coefficient  = -5.0x10-5 oC-1. The length of the resistor is 1.0x10-2 m and the radius is 1.0x10-4m.a. What is the cross sectional area of the wire?b. Determine the resistance at 20oC.c. What is the resistivity and resistance at 150oC?5. Consider the electrons of a car battery traveling along a wire toward a starting motor. Assume that a current of 300 A travels along copper wire (diameter = 0.3 cm and length = 0.85 m) and the # of charge carriers is 8.49x1028 m-3.a. Determine the cross sectional area of the wire.b. What is the drift velocity of the electrons in this current?c. How long will it take electrons to get from a car battery to the motor?6. The bulb of a typical light bulb is conducts 0.3 A of current at 2.9 V. At room temperature, 20oC, the resistance of the tungsten filament is 1.1 .a. What is the resistance of the bulb filament at 2.9 V?b. What is the temperature of the illuminated tungsten filament?c. How thick is the tungsten filament if the length of filament is 2.0 cm?Phy 213: General Physics III 1/14/2019Chapter 26 Worksheet 37. Using the textbook equation for temperature dependence, estimate the temperature where the resistivity of lead should be zero, i.e. it becomes a superconductor. Note: Regardless of your estimate, the textbook model fails. Lead becomes a superconductor at 7K and below.8. Estimate the temperature that copper is predicted to become a superconductor. Note: Copper never actually becomes a superconductor even down to near 0K.9. Estimate the temperature that silicon is predicted to become a superconductor. Note: Silicon, slightly doped with impurities, achieves superconductivity even down to near 0K.10. An electrical cable consists of 125 strands, each with a resistance of 2.65 . A constant potential difference is applied across the cable resulting in current of 0.75 A along the cable.a. What is the current in each strand?b. What is the applied potential difference?c. What is the resistance of the cable?11. A certain space heater, operating at 120V, dissipates heat energy at a rate of 500 W during operation.a. What is the resistance of the heater during operation?b. How much current flows through the heating element during operation?c. At what rate do electrons flow through any given cross section of the heater element?d. What is the rate of heat energy transfer per coulomb?e. What is the rate of heat energy transfer per