• Nature of Resistance Temperature-Resistance Relationship Ohm's Law, Energy and Power Kirchhoff's Law • Maxwell's Mesh Analysis 1. A coil of copper wire (p = 10.37 2-cmil/ft) has a length of 600 ft. What is the length of an aluminum conductor (p 17 cmil/ft), if its cross-sectional area and resistance are the same as those of the copper coil? (Hint: Look for conversion of inches to mils and square inches to square foot. Include it in your solution.) (1 pt) 2. The copper field winding of an electric machine has a resistance of 46 at temperature of 22°C. What will be its resistance at 75°C? (Use do = 0.00427 /°C for copper) (1 pt) 3. The resistivity of a copper rod 50 ft long and 0.25 inch in diameter is 1.76 μ at 20°C. What is its resistance at - 20°C? (1 pt) 4. When two resistors A and B are connected in series, the total resistance is 36 2. When connected in parallel, the total resistance is 8 Q. What is the ratio of the resistance RA to resistance RB? Assume RA < RB. (1 pt) 5. The equivalent resistance of three resistors A, B and C connected in parallel is 12/7. If A is twice as B, and C is half as much as B, find the equivalent resistance when the three of them are connected in series. (2 pts) 6. The resistance of an incandescent lamp is 10 and the rated voltage is 50 V. Find the series resistance required to operate the lamp from an 80 V supply. (2 pts) 7. Two resistors with resistance of 10 and 15 are connected in parallel. The two are connected in series with a 5- resistance. It is then connected across a 12-V battery. What are the currents flowing in each resistor, power dissipations of each resistor and the total power of the circuit? (2 pts) For items 8-9, refer to the problem below. Find all the currents flowing in every resistor, power dissipation in every resistor and the total power of the circuit shown at the right using... 8. Kirchhoff's Laws (5 pts) 9. Maxwell's Mesh Analysis (5 pts) + - 8 V B wwwww 10 V + 20 Ω €302 A www 202 wwww C 202 502 12 V