It is necessary to band an armature with us of steel wire per band If the armature has a diameter of 20 inches, how many feet of wire are necessary per band, allowing 1.5 feet per band for waste and tightening? 5. A commutator has a diameter of 2.375 inches. What is the circumfer 6. If I cubic inch of copper weighs 0.314 pound, find the weight of a piece 7. What is the weight of l gallon of sulphuric acid if 1 cubic inch weighs 8. What is the resistance of the piece of copper wire shown in this figure 4 UNIT 13 MULTIPLICATION OF DECIMAL FRACTIONS 71 ence to the nearest thousandth of the commutator? of copper that contains 2.25 cubic inches. 0.0665 pound? (231 cubic inches - 1 gallon) that has a size of 2.5 mil-feet if 1 mil-foot has a resistance of 10 ohms? COPPER WIRE 1 MIL = 0.001 INCH 1 FOOT 9. An electric meter registers 8,749 kilowatt-hours on July 1 and 8,930 kilowatt-hours on August 1. The difference between these values is the total amount of energy used during this period. At $0.35 per kilowatt-hour, find the cost of the energy used. 10. What is the cost of 1,250 feet of cable at $23.25 per one hundred feet? 11. What is the cost of 1,750 feet of BX cable if it sells for $0.6823 per foot? 12. What is the tax bill for a contractor if his shop has an assessed valuation of $35,000, and the tax rate is $27.50 per thousand dollars of assessed valuation? cost 1991 13. A truck is known to consume about 0.12 gallon of gas per mile. If it is driven 18,500 miles and gas costs $1.869 per gallon, what is the for gas?