Comprehensive Problems
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Comprehensive Problems
- 1.32 A telephone wire has a current of 20ฮผA flowing through it. How long does it take for a charge of 15 C to pass through the wire?
- 1.33 A lightning bolt carried a current of 2 kA and lasted for 3 ms. How many coulombs of charge were contained in the lightning bolt?
- 1.34 Figure 1.32 shows the power consumption of a certain household in 1 day. Calculate:
- (a) the total energy consumed in kWh,
- (b) the average power over the total 24 hour period.
For Prob. 1.34.
1.35 The graph in Fig. 1.33 represents the power drawn by an industrial plant between 8:00 and 8:30 a.m. Cal culate the total energy in MWh consumed by the plant.
For Prob. 1.35.
1.36 A battery can be rated in ampere-hours (Ah) or watt hours (Wh). The ampere hours can be obtained from the watt hours by dividing watt hours by a nominal
voltage of 12 V. If an automobile battery is rated at 20 Ah:
- (a) What is the maximum current that can be supplied for 15 minutes?
- (b) How many days will it last if it is discharged at a rate of 2 mA?
- 1.37 A total of 2 MJ are delivered to an automobile battery (assume 12 V) giving it an additional charge. How much is that additional charge? Express your answer in ampere-hours.
- 1.38 How much energy does a 10-hp motor deliver in 30 minutes? Assume that 1 horsepower = 746 W.
- 1.39 A 600-W TV receiver is turned on for 4 h with nobody watching it. If electricity costs 10 cents/kWh, how much money is wasted?
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