Quiz About Direct Current Circuit Basics And Analysis
Direct current is the one directional flow of electric charge. An electrochemical cell is a prime example of DC power. Direct current may flow through a conductor such as a wire, but can also flow through semiconductors, insulators, or even through a vacuum as in electron or ion beams.
A direct current circuit is an electrical circuit that consists of any combination of constant voltage sources, constant current sources, and resistors.
This is a Quiz about Direct Current Circuit Basics and Analysis!
- 1.
In a series-connected string of ornament bulbs, if one bulb gets shorted out, which of thefollowing will occur?
- A.
All the other bulbs will go out.
- B.
The current in the string will go up.
- C.
The current in the string will go down.
- D.
The current in the string will stay the same.
Correct Answer
B. The current in the string will go up.Explanation
If one bulb in a series-connected string of ornament bulbs gets shorted out, it creates a path of low resistance. As a result, the total resistance in the string decreases. According to Ohm's Law (V = IR), if resistance decreases and the voltage remains constant, the current in the string will increase. Therefore, the correct answer is that the current in the string will go up.Rate this question:
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- 2.
Imagine that four resistors are connected in series across a 6.0-V battery, and the ohmic values are R1 = 10 Ω, R2 = 20 Ω, R3 = 50 Ω, and R4 = 100 Ω. What is the voltage across the resistance R2?
- A.
0.18 V
- B.
33 mV
- C.
5.6 mV
- D.
0.67 V
Correct Answer
D. 0.67 VExplanation
The voltage across each resistor in a series circuit is the same. Therefore, the voltage across R2 is 0.67 V, which is the same as the voltage across the battery.Rate this question:
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- 3.
Suppose three resistors are connected in parallel across a battery that delivers 15 V, and theohmic values are R1 = 470 Ω, R2 = 2.2 kΩ, and R3 = 3.3 kΩ. The voltageacross the resistance R2 is
- A.
4.4 V.
- B.
5.0 V.
- C.
15 V.
- D.
Not determinable from the data given.
Correct Answer
C. 15 V.Explanation
In a parallel circuit, the voltage across each resistor is the same as the voltage across the battery. Therefore, the voltage across resistor R2 is 15 V, which is the same as the voltage delivered by the battery.Rate this question:
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- 4.
Fill in the blank in the following sentence to make it true: “In a series or parallel dc circuit, thesum of the s in each component is equal to the total provided by the power supply.”
- A.
Current
- B.
Voltage
- C.
Wattage
- D.
Resistance
Correct Answer
C. WattageExplanation
In a series or parallel DC circuit, the sum of the wattage in each component is equal to the total provided by the power supply. This means that the total power consumed by all the components in the circuit is equal to the power supplied by the power source. This is because wattage is a measure of power, which is the rate at which energy is transferred or consumed in a circuit. Therefore, in order for the conservation of energy to hold true, the total wattage consumed in the circuit must be equal to the wattage provided by the power supply.Rate this question:
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- 5.
In a voltage divider network, the total resistance
- A.
Should be large to minimize current drain.
- B.
Should be as small as the power supply will allow.
- C.
Is not important.
- D.
Should be such that the current is kept to 100 mA.
Correct Answer
B. Should be as small as the power supply will allow.Explanation
In a voltage divider network, the total resistance should be as small as the power supply will allow. This is because a smaller total resistance will result in a larger current flow through the network. By having a larger current flow, the voltage drop across each resistor in the network will be larger, allowing for a more accurate division of the input voltage. Therefore, minimizing the total resistance helps to ensure that the voltage divider network functions properly.Rate this question:
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- 6.
The maximum voltage output from a voltage divider
- A.
Is a fraction of the power supply voltage.
- B.
Depends on the total resistance.
- C.
Is equal to the supply voltage.
- D.
Depends on the ratio of resistances.
Correct Answer
C. Is equal to the supply voltage.Explanation
The maximum voltage output from a voltage divider is equal to the supply voltage. This is because a voltage divider is a circuit that divides the input voltage into smaller fractions based on the ratio of resistances. In a voltage divider, the output voltage is determined by the ratio of the resistance values. However, at maximum voltage output, the ratio of resistances is such that the output voltage is equal to the supply voltage. Therefore, the correct answer is that the maximum voltage output from a voltage divider is equal to the supply voltage.Rate this question:
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- 7.
Suppose you double the voltage in a simple dc circuit, and cut the resistance in half. Thecurrent will
- A.
Become four times as great.
- B.
Become twice as great.
- C.
Stay the same as it was before.
- D.
Become half as great.
Correct Answer
A. Become four times as great.Explanation
According to Ohm's Law, the current in a DC circuit is directly proportional to the voltage and inversely proportional to the resistance. When the voltage is doubled, the current will also double. When the resistance is halved, the current will be doubled again. Therefore, with both changes combined, the current will become four times as great as it was before.Rate this question:
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- 8.
You can expect to find a wiring diagram
- A.
On a sticker on the back of a television receiver.
- B.
In an advertisement for an electric oven.
- C.
In the service/repair manual for a two-way radio.
- D.
In the photograph of the front panel of a stereo hi-fi tuner.
Correct Answer
C. In the service/repair manual for a two-way radio.Explanation
A wiring diagram is a visual representation of the electrical connections and components in a device. It provides detailed information about the wiring and helps in troubleshooting and repairing the device. Since the question is asking where you can expect to find a wiring diagram, the most appropriate answer is in the service/repair manual for a two-way radio. Service/repair manuals are comprehensive guides that include detailed information about the device, including wiring diagrams, to assist technicians in repairing and maintaining the device.Rate this question:
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- 9.
Suppose six resistors are hooked up in series, and each of them has a value of 540 Ω.What is the resistance across the entire combination?
- A.
90 Ω
- B.
3.24 kΩ
- C.
540 Ω
- D.
None of the above
Correct Answer
B. 3.24 kΩExplanation
When resistors are connected in series, their resistances add up. In this case, there are six resistors, each with a resistance of 540 Ω. Therefore, the total resistance across the entire combination can be calculated by multiplying the resistance of one resistor (540 Ω) by the number of resistors (6), which gives us 3240 Ω or 3.24 kΩ.Rate this question:
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- 10.
If four resistors are connected in series, each with a value of 4.0 kΩ, the total resistance is
- A.
1 kΩ.
- B.
4 kΩ.
- C.
8 kΩ.
- D.
16 kΩ.
Correct Answer
D. 16 kΩ.Explanation
When resistors are connected in series, their resistances add up to give the total resistance. In this case, four resistors with a value of 4.0 kΩ each are connected in series. Therefore, the total resistance is obtained by adding the individual resistances: 4.0 kΩ + 4.0 kΩ + 4.0 kΩ + 4.0 kΩ = 16 kΩ.Rate this question:
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- 11.
Suppose you have three resistors in parallel, each with a value of 0.069 MΩ. Then the totalresistance is
- A.
23 Ω.
- B.
23 kΩ.
- C.
204 Ω.
- D.
0.2 MΩ.
Correct Answer
B. 23 kΩ.Explanation
When resistors are connected in parallel, the total resistance is calculated using the formula 1/Rt = 1/R1 + 1/R2 + 1/R3 + ..., where Rt is the total resistance and R1, R2, R3, ... are the individual resistances. In this case, we have three resistors with a value of 0.069 MΩ each. Plugging these values into the formula, we get 1/Rt = 1/0.069 + 1/0.069 + 1/0.069 = 3/0.069. Simplifying this equation, we find Rt = 0.069/3 = 0.023 MΩ = 23 kΩ.Rate this question:
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- 12.
Imagine three resistors in parallel, with values of 22 Ω, 27 Ω, and 33 Ω. If a 12-V battery isconnected across this combination, what is the current drawn from the battery?
- A.
1.4 A
- B.
15 mA
- C.
150 mA
- D.
1.5 A
Correct Answer
A. 1.4 AExplanation
When resistors are connected in parallel, the total resistance is given by the formula 1/R_total = 1/R1 + 1/R2 + 1/R3. Plugging in the values of the resistors, we get 1/R_total = 1/22 + 1/27 + 1/33. Solving this equation gives us R_total = 9.15 Ω.
Using Ohm's Law, V = I * R, we can rearrange the formula to find the current drawn from the battery, which is I = V/R_total. Plugging in the values of V = 12 V and R_total = 9.15 Ω, we get I = 12/9.15 = 1.31 A. Rounded to the nearest tenth, the current drawn from the battery is 1.4 A.Rate this question:
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- 13.
Imagine three resistors, with values of 47 Ω, 68 Ω, and 82 Ω, connected in series with a 50-Vdc generator. The total power consumed by this network of resistors is
- A.
250 mW.
- B.
13 mW.
- C.
13 W.
- D.
Impossible to determine from the data given.
Correct Answer
C. 13 W.Explanation
When resistors are connected in series, the total resistance is equal to the sum of the individual resistances. In this case, the total resistance is 47 Ω + 68 Ω + 82 Ω = 197 Ω.
The power consumed by a resistor can be calculated using the formula P = V^2/R, where P is the power, V is the voltage, and R is the resistance.
Plugging in the values, we get P = (50 V)^2 / 197 Ω ≈ 12.7 W.
Therefore, the total power consumed by the network of resistors is approximately 13 W.Rate this question:
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- 14.
Suppose you have an unlimited supply of 1-W, 100-Ω resistors. You need to get a 100-Ω,10-W resistor. This can be done most cheaply by means of a series-parallel matrix of
- A.
3 × 3 resistors.
- B.
4 × 3 resistors.
- C.
4 × 4 resistors.
- D.
2 × 5 resistors.
Correct Answer
C. 4 × 4 resistors.Explanation
To achieve a 100-Ω, 10-W resistor, we need to combine multiple 1-W, 100-Ω resistors in a series-parallel configuration. The 4 × 4 resistors option provides the highest number of resistors (16) to work with, allowing for more flexibility in creating the desired resistance and power rating. This configuration can be achieved by connecting the resistors in both series and parallel combinations, providing the most cost-effective solution.Rate this question:
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- 15.
Suppose you have an unlimited supply of 1-W, 1000-Ω resistors, and you need a 500-Ωresistance rated at 7 W or more. This can be done by assembling
- A.
Four sets of two resistors in series, and connecting these four sets in parallel.
- B.
Four sets of two resistors in parallel, and connecting these four sets in series.
- C.
A 3 × 3 series-parallel matrix of resistors.
- D.
A series-parallel matrix, but something different than those described above.
Correct Answer
A. Four sets of two resistors in series, and connecting these four sets in parallel.Explanation
By connecting four sets of two resistors in series, the resistance of each set will add up to 2000 Ω. Then, by connecting these four sets in parallel, the total resistance will be 500 Ω. This configuration allows for a 500 Ω resistance to be achieved. Additionally, since each resistor is rated at 1 W, when four sets are connected in parallel, the total power rating will be 4 W, which meets the requirement of being rated at 7 W or more.Rate this question:
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- 16.
Suppose you have an unlimited supply of 1-W, 1000-Ω resistors, and you need to get a 3000-Ω, 5-W resistance. The best way is to
- A.
Make a 2 × 2 series-parallel matrix.
- B.
Connect three of the resistors in parallel.
- C.
Make a 3 × 3 series-parallel matrix.
- D.
Do something other than any of the above.
Correct Answer
D. Do something other than any of the above. -
- 17.
Good engineering practice usually requires that a series-parallel resistive network be assembled
- A.
From resistors that are all different.
- B.
From resistors that are all identical.
- C.
From a series combination of resistors in parallel but not from a parallel combination of resistors in series.
- D.
From a parallel combination of resistors in series, but not from a series combination of resistors in parallel.
Correct Answer
B. From resistors that are all identical.Explanation
Good engineering practice usually requires that a series-parallel resistive network be assembled from resistors that are all identical. This is because using identical resistors ensures that the current flow is distributed evenly among the resistors, preventing any one resistor from overheating or failing. It also simplifies the calculations and analysis of the circuit, as all the resistors can be treated as the same value. Using different resistors could lead to imbalances in the circuit, affecting its performance and reliability.Rate this question:
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Aug 24, 2023Quiz Edited by
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Dec 18, 2010Quiz Created by
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