Current and Resistance83(b) The energy used by the oven in 5.0 h is ()31 kW20.0 C s220 J C5.0 h22 kWh10 J sEtIVt=⋅∆=∆⋅∆==Pand the cost of this energy, at a rate of $0.12 per kilowatt-hour is ( )22 kWh$0.12 kWh$2.6costE rate=⋅==17.33The maximum power that can be dissipated in the circuit is ( ) ( )( )3maxmax120 V15 A1.810 WVI=∆==×PThus, one can operate at most 18 bulbs rated at 100 W per bulb. 17.34(a) The power loss in the line is ( )( )2271000 A0.31 km160 km5.050 MWlossIR==Ω=×=P(b) The total power transmitted is ( )( )3870010 V7.0700 MWinput=×=×=PThus, the fraction of the total transmitted power represented by the line losses is
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This note was uploaded on 12/09/2011 for the course PHYS 2020 taught by Professor Staff during the Fall '10 term at FIU.