Honors Physics Chapter 17 Review 1. As a particle moves 5 m ...

Honors Physics Chapter 17 Review
1. As a particle moves 5 m along an electric field of strength 100 N/C, its electrical
potential energy decreases by 4x10 -16 J.
a. What is the particle’s charge? (Answer: 8x10 -19 C)
b. What is the potential difference between the initial and final locations of the
particle? (Answer: -500 V)
2. An electron is released from rest in a uniform electric field with a magnitude of
6x10 4 V/m. The electron is displaced 0.75 m as a result.
a. Find the potential difference between the electron’s initial and final positions.
(Answer: -4.5x10 4 V)
b. Find the change in electrical potential energy of the electron as a result of this
displacement.
(Answer: 7.2x10 -15 J)
3. A 2 µF capacitor is connected to a 6 V battery.
a. What is the charge on each place of the capacitor? (Answer: 1.2x10 -5 C)
b. If this same capacitor is connected to a 3 V battery, how much electrical potential
energy is stored? (Answer: 9x10 -6 J)
4. A parallel-place capacitor has a charge of 6 µC when charged by a potential
difference of 1.5 V.
a. Find its capacitance. (Answer: 4x10 -6 F)
b. How much electrical potential energy is stored when this capacitor is connected to
a 6 V battery? (Answer: 7.2x10 -5 J)
5. A capacitor has a capacitance of 4 pF.
a. What potential difference would be required to store 12 pC? (Answer: 3 V)
b. How much charge is stored when the potential difference is 12V? (4.8 x10 -11 C)
6. You are asked to design a parallel-plate capacitor having a capacitance of 2 F and a
plate separation of 1 mm. Calculate the required surface area of each plate.
(Answer: 2.26x10 8 m 2 )
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7. A parallel plate capacitor has an area of 4 cm 2 , and the plates are separated by c 10
-3
4 mm.
m 10
a. What is the capacitance? (Answer: 8.85x10 -13 F)
6
10
b. How much charge does this capacitor store when connected to an 18 V battery?
-9
n 10
(Answer: 1.6x10 -11 C)
12
p 10
8. If a metal wire carries a current of 80 mA, how long does it take for 4x10 20 electrons to pass a given crosssectional
area of the wire? (Answer: 800 s)
9. The compressor on an air conditioner draws 60 A when it starts up. If the start-up time is 4 s, how much
charge passes a cross-sectional area of the circuit in this time? (Answer: 240 C)
10. A net charge of 750 mC passes through the cross-sectional area of a wire in 25 seconds.
a. What is the current in the wire? (Answer: 0.03 A)
b. How many electrons pass the cross-sectional area in 3 minutes? (Answer: 3.375×10 19 electrons)
19
2
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11. A color television draws 7 A of current when connected across a potential
difference of 110V. What is the effective resistance of the television set?
(Answer: 15.71 Ω)
12. How much current is drawn by a stereo with a resistance of 25 Ω that is connected
across a potential difference of 90 V? (Answer: 3.6 A)
13. The current in a certain resistor is 8 A when it is connected to a potential difference
of 130 V. What is the current in the same resistor if the operating potential is 120 V?
(Answer: 7.38 A)
14. The current in a heater is 65 A, and the resistance of the oven’s circuitry is 2 Ω.
a. What is the potential difference across the wire? (Answer: 130 V)
b. How much power does the heater dissipate? (Answer: 8,450 W)
15. The operating potential difference of a light bulb is 90 V. The power rating of the
bulb is 60 W.
a. Find the bulb’s resistance. (Answer: 135 Ω)
b. Find the current in the bulb. (Answer: 0.67 A)
16 Calculate the cost of operating a 100 W light bulb continuously for a two weeks
when electrical energy costs $0.07/kW·h. (Answer: $2.35)
There will also be conceptual questions so you will need to review your notes and text.
Things to know:
Difference between electrical potential energy, electrical potential, and potential
difference
Charges gaining or losing potential energy as they move through an electric
field (pg. 595)
How a battery works and provides energy for charge movement (pg. 600)
What capacitance is, how a capacitor stores energy, how a capacitor is made,
what a dielectric is, what factors affect the amount of energy stored
What electric current is, what 1 ampere is equivalent to, conventional current vs.
movement of charge carriers, drift velocity vs. average speed between collisions,
difference between ohmic and non-ohmic materials, factors that affect resistance
Difference between batteries and generators
Difference between direct and indirect current
What power rating is and what is means
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