Physics equations/20- Electric Current, Resistance, and Ohm's Law/Q:PowerDriftVelocity

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A

1 A 4 volt battery moves 27 Coulombs of charge in 2.6 hours. What is the power?

	a) 7.86 x 10-3 W
	b) 9.52 x 10-3 W
	c) 1.15 x 10-2 W
	d) 1.4 x 10-2 W
	e) 1.69 x 10-2 W

2 The diameter of a copper wire is 5.5 mm, and it carries a current of 76 amps. What is the drift velocity if copper has a density of 8.8E3 kg/m³ and an atomic mass of 63.54 g/mol? (1 mol = 6.02E23 atoms, and copper has one free electron per atom.)

	a) 1.35 x 10-4m/s
	b) 1.63 x 10-4m/s
	c) 1.98 x 10-4m/s
	d) 2.39 x 10-4m/s
	e) 2.9 x 10-4m/s

3 A 168 Watt DC motor draws 0.3 amps of current. What is effective resistance?

	a) 1.87 x 103 Ω
	b) 2.26 x 103 Ω
	c) 2.74 x 103 Ω
	d) 3.32 x 103 Ω
	e) 4.02 x 103 Ω

4 A power supply delivers 113 watts of power to a 104 ohm resistor. What was the applied voltage?

	a) 5.03 x 101 volts
	b) 6.1 x 101 volts
	c) 7.39 x 101 volts
	d) 8.95 x 101 volts
	e) 1.08 x 102 volts