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Electric Current

1. A charge of 1020 C was passed through a wire in 5.5 min. What was the average electric current during that interval?

2. How long does it take for 67 C to pass a given point in a wire that carries an electric current of 0.80 A?

3. What is the potential difference across a 220 ohm resistor when a current of 3.50 A flow through it?

4. A piece of Nichrome wire passes a current of 0.853 A when a potential of 1.64 V is applied. What is the resistance of the wire?

5. Calculate the resistance of a piece of 20-gauge copper wire 2.00 m long. The cross-sectional area of 20-gauge wire is 0.5176 mm^2.

6. Compute the resistances of 18-gauge and 16-gauge copper wires of 5.00 m long. The cross-sectional area of 18 gauge wire is 0.8231 mm^2, and that of 16 gauge wire is 1.309 mm^2.

7. A flashlight lamp connected to battery that provides 1.4 V draws a current of 0.10 A. What electric power is used by the lamp?

8. A 150-W street lamp is operated for 12 hours a day. How much energy does it take to operate the lamp for 30 days? Express your answer in kilowatt-hours and in joules.

Solution Preview

1.)
Charge Q = 1020 C
time t = 5.5 min = 5.5*60 = 330 sec
Because, current
I = Q/t = 1020/330 = 3.09 == 3.1 Ampere --Answer

2.)
Electric current I = 3.50 A
Charge Q = 67 C
Therefore, time
t = Q/I = 67/3.5 = 19.14 sec --Answer

3.)
Resistance R = 220 ohm
current I = 3.50 A
Potential difference V = I*R = ...

Solution Summary

The answers are given step-by-step.

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