Transcript 23__electric_current..

23.1
23.2
23.3
23.4
Hydraulic circuit
Electric circuit
23.5
23.6
Direct & Alternating Current
Diode  AC  DC
Diode  AC  DC
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Electric Current
23.8
Series Circuit
Req = R1 + R2 + R3
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Parallel Circuit
1/Req = 1/R1 + 1/R2 + 1/R3
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23.11
-- Questions -MULTIPLE CHOICE.
Choose the one alternative that
best completes the statement or
answers the question.
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1) The source of electrons lighting an incandescent ac light bulb is
A) the wire leading to the lamp.
B) electrical outlet.
C) the source voltage.
D) the power company.
E) atoms in the light bulb filament.
2) A circuit is powered with a battery. Charge flows
A) from the negative battery terminal to the positive terminal.
B) through both the battery and the rest of the circuit.
C) after a couple seconds passes.
D) out of the battery and into the circuit.
E) none of these.
23.13
3) If you plug an electric toaster rated at 110 V into a 220-V outlet, the
current in the toaster will be about
A) twice what it should be.
B) the same as if it were plugged into 110 V.
C) more than twice what it should be.
D) half what it should be.
4) Electrons move in an electrical circuit
A) by being bumped by other electrons.
B) because the wires are so thin.
C) by colliding with molecules.
D) by interacting with an established electric field.
E) none of these.
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5) Two lamps, one with a thick filament and one with a thin filament, are
connected in parallel to a battery. The voltage is greatest across the
lamp with the
A) thick filament.
B) thin filament.
C) both voltages are the same.
6) A capacitor is used to store
A) charge.
B) energy.
C) both.
D) neither.
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7) What is the power rating of a light bulb if 0.8 A flow through it when
it is connected to a 120-volt outlet?
A) 12 W
B) 15 W
C) 60 W
D) 96 W
E) 120 W
8) A woman experiences an electrical shock. The electrons making the
shock come from the
A) hairdryer.
B) power plant.
C) woman's body.
D) electric field in the air.
E) ground.
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9) A 10-ohm resistor has a 5-A current in it. What is the voltage across
the resistor?
A) 5 V
B) 10 V
C) 15 V
D) 20 V
E) more than 20 V
10) Connect a pair of lamps in series and you draw current from the
connected battery. Connect the same lamps in parallel and you draw
A) more current.
B) the same current.
C) less current.
D) ...sometimes more, sometimes less.
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11) Two lamps, one with a thick filament and one with a thin filament,
are connected in series. The current is greater in the lamp with the
A) thick filament.
B) thin filament.
C) the same in each lamp.
12) The current through a 10-ohm resistor connected to a 120-V power
supply is
A) 1 A.
B) 10 A.
C) 12 A.
D) 120 A.
E) none of these.
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13) When a pair of 1-ohm resistors are connected in series, their
combined resistance is
A) 2 ohms, and when in parallel, 1/2 ohm.
B) 1 ohm, and when connected in parallel, 2 ohms.
C) 2 ohms, and when in parallel, 1 ohm.
D) 1/2 ohm, and when in parallel, 2 ohms.
E) none of these.
14) Which statement is correct?
A) Resistance is established across a circuit.
B) Current causes voltage.
C) Voltage flows through a circuit.
D) Charge flows in a circuit.
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15) An electrical diode is useful for
A) voltage modification.
B) changing ac to dc.
C) limiting current.
D) storing electrical energy.
E) boosting voltage.
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-- Answers -MULTIPLE CHOICE.
The one alternative that best
completes the statement or
answers the question.
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Chapter 23
1) Answer: E
2) Answer: B
3) Answer: A
4) Answer: D
5) Answer: C
6) Answer: C
7) Answer: D
8) Answer: C
9) Answer: E
10) Answer: A
11) Answer: C
12) Answer: C
13) Answer: A
14) Answer: D
15) Answer: B
23.22