Electrotechnology Certificate 1 UEENEE040B: Reference ...



Section 1

|Section |Question |Response |

|1-1 |1.How does a fundamental unit differ from a derived unit? | |

| |2 .What is the fundamental electrical units | |

| |3. What does SI stand for? | |

| |4. Without referring to the table 1-3 list as many | |

| |electrical qualities as possible, including their symbols,| |

| |units and unit symbols | |

| |5.Without referring to table 1-4 , list as many magnetic | |

| |qualities as possible, including their symbols, units and | |

| |unit symbols | |

|Section |Question |Response |

|1-2 |1.Scientific notation uses powers of ten(T or F) | |

| |2.Express 100 as a power of ten | |

| |3.Express the following nos. in scientific notation. A. 4 | |

| |350 B.12 010 C.29 000 000 | |

| |4.Express the following nos. in scientific notation. A. | |

| |0.760 B.0.00025 C.0.000000597 | |

| |5.Do the following operations: | |

| |A.(1x105) +(2x105) B. (3x106)(2x104) | |

| |C.8x103)/(4x102) | |

| |D.(2.5x10-6)-(1.3x10-7) | |

|Section |Question |Response |

|1-3 |1.Express the following in engineering notation: A.0.0056 | |

| |B.0.000000283 C.950 000 D.375 000 000 000 | |

| |2.List the metric prefix for each of the following powers | |

| |of ten: 106,103, | |

| |10-3,10-6,10-9, 10-12 | |

| |3.Use an appropriate metric prefix to express 0.000001A | |

| | | |

| |4. Use an appropriate metric prefix to express 250 000W | |

|Section |Question |Response |

|1-4 |1.Convert 0.01 MVto kilovolts(kV) | |

| |2.Convert 250 000pA to milliamperes(mA) | |

| |3.Add 0.05 MW and 75 kW and express the result in kW | |

| |4.Add 50mV and25 000 µV and express the result in mV | |

|Gen. Test |Question |Response |

| |1.Which is not an electrical quantity? | |

| |A.current B.voltage C.time D.power | |

| |2.The unit of current is | |

| |A.Volt B.watt C.ampere D.joule | |

| |3.The unit of voltage is | |

| |A.ohm B.watt C.volt D.farad | |

| |4.The unit of resistance is | |

| |A.ampere B.henry C.frequency D.ohm | |

| |5.Hertz is the unit of | |

| |A.power B.inductance C.frequency D.time | |

| |6.15 000 W is the same as | |

| |a.15mW B.15kW C.15MW D.15µW | |

| |7.The quantity 4.7 x 103 is the same as | |

| |A.470 B.4700 C.47 000 D.0.0047 | |

| |8.The quantity 56x10-3 is the same as | |

| |A.0.056 B.0.560 C.560 D.56 000 | |

| |9.The number 3 300 000can be expressed in engineering | |

| |notation as | |

| |A.3300x103 B.3.3x10-6 C.3.3x106 D.either a or b | |

| |10.Ten milliamperes can be expressed as | |

| |A.10MA B.10µA C.10kA D.10mA | |

| |11.Five thousand volts can be expressed as | |

| |A.5000V B.5MV C.5kV D.either a or c | |

| | | |

| | | |

| |12.Twenty million ohms can be expressed as | |

| |A.20mµ B20MW C.20MΩ D.20µΩ | |

| | | |

Section 2

|Section |Question |Response |

|2-1 |1.What is the basic particle of negative charge? | |

| |2 .Define atom | |

| |3. What does an atom consist of? | |

| |4. Define atomic number | |

| |5. Do all elements have the same type of atoms? | |

| |6. What is a free electron? | |

| |7. What is a shell in the atomic structure? | |

| |8. Name two conductive materials | |

|Section |Question |Response |

|2-2 |1. What is the symbol for charge? | |

| |2. What is the unit of charge? What is the symbol? | |

| |3. What causes positive and negative charge? | |

| |4. How much charge in coulombs is there in 10x1012 | |

| |electrons | |

|Section |Question |Response |

|2-3 |1. Define voltage | |

| |2.What is the unit of voltage? | |

| |3.How much is the voltage when there are 24 joules of | |

| |energy for ten coulombs of charge? | |

| |4. Define current and state it’s unit | |

| |5. How many electrons make up one unit of charge? | |

| |6.What is the current in amperes when 20c flow past a | |

| |point in a wire in 4 s? | |

| |7. Define resistance | |

| |8. What is the unit of resistance? | |

| |9. Define one ohm | |

|Section |Question |Response |

|2-4 |1.Define voltage source | |

| |2.Explain how a battery produces voltage | |

| |3.Describe how a solar cell produces voltage | |

| |4.Discuss how an electrical generator creates voltage | |

| |5.Explain what an electric power supply does | |

| |6. Define a current source | |

| |7.Name an electronic component that is used as a current | |

| |source | |

|Section |Question |Response |

|2-5 | | |

| |1. What are the 2 main categories of resistors? Explain | |

| |the difference | |

| |2. In the 4 band resistor colour code, what does each band| |

| |represent? | |

| |3.Determine the resistance and the percent tolerance for |a. |

| |each of the resistors in figure 2-37 |b. |

| | |c. |

| | |d. |

| | |e. |

| | |f. |

| |4.From the selection of resistors in figure 2-38, select |330Ω |

| |the following values; |2.2kΩ |

| | |56kΩ |

| | |100kΩ |

| | |39kΩ |

| |5. What is resistance value is indicated by each |a. 33R: |

| |alphanumeric symbol? |b. 5K6: |

| | |c. 900: |

| | |d. 6M8: |

| |6.What is the basic difference between a rheostat and a | |

| |potentiometer? | |

| |7.What is a thermistor? | |

|Section |Question |Response |

|2-6 | | |

| |1. What are the basic elements of an electric circuit? | |

| |2. What is an open circuit? | |

| |3.What is a closed circuit? | |

| |4.What is the difference between a fuse and a circuit | |

| |breaker? | |

| |5. Which wire is larger in diameter, AWG 3 or AWG22? | |

| |6. What is ground (common) in an electrical circuit? | |

|Section |Question |Response |

|2-7 | | |

| |1. Name the meters for measurement of; a.current b. | |

| |voltage c.resistance | |

| |2. Place 2 ammeters in the circuit of figure 2-42 to | |

| |measure the current through either lamp (be sure to | |

| |observe polarities) . How can the same measurements be | |

| |accomplished with only one ammeter? Draw your answer | |

| |3. Show how to place a voltmeter to measure to measure the| |

| |voltage across lamp 2 in figure 2-42 | |

| |4. List 2 common types of of DMM displays and discuss the | |

| |advantages and disadvantages of each | |

| |5.Define resolution in a DMM | |

| |6.The multimeter in figure 2-60 is set on the 3V range to | |

| |measure the DC voltage. The pointer is at 150 on the upper| |

| |ac/dc scale. What is the voltage being measured? | |

| |7. How do you set up the meter in figure 2-60 to measure | |

| |275V dc , and on what scale do you read the voltage? | |

| |8. If you expect to measure a resistance in excess of | |

| |20kΩ, where do you set the switch? | |

|Section |Question |Response |

|2-8 | | |

| |1. What causes physical pain and/or damage to the body | |

| |when electrical contact is made? | |

| |2. Is it ok to wear a ring when working on an electrical | |

| |circuit? | |

| |3. Is it ok to stand on a wet floor when working on an | |

| |electrical circuit? | |

| |4. Can a circuit be rewired without removing the power if| |

| |you are careful? | |

| |5. Electrical shock can be extremely painful or even fatal| |

| |(T or F) | |

|Gen. Test |Question |Response |

| |1. A neutron atom with an atomic number of 3 has how many | |

| |electrons | |

| |2. Electron orbits are called? | |

| |3.Materials in which there is no current when voltage is | |

| |applied are called? | |

| | | |

| | | |

| | | |

| |4.When placed close together a positively charged and a | |

| |negatively charged material will? | |

| |5. The charge on a single electron is? | |

| |6.Potential difference is another term for? | |

| |7.The unit f energy is? | |

| |8.Which is not a type of energy source; a. battery b. | |

| |solar cell c. generator d. potentiometer | |

| |9.Which is not a possible condition in an electric circuit| |

| |A.voltage & no current B.Current and no voltage C.voltage | |

| |and current D.no voltage & no current | |

| |10.Electrical current is defined as? | |

| |11.There is no current in a circuit when? | |

| |12.The primary purpose of a resistor is? | |

| | | |

| | | |

| |13. Potentiometers and rheostats are types of | |

| |14. The current in a given circuit is not to exceed 22A. | |

| |Which value fuse is best? | |

Section 3

|Section |Question |Response |

|3-1 |1.Ohm’s law defines how 3 basic quantities are related. | |

| |What are they? | |

| |2 .Write Ohm’s law formula for current | |

| |3. Write Ohm’s law formula for voltage | |

| |4. Write Ohm’s law formula for resistance | |

| |5. If the voltage across a fixed-value resistor is | |

| |tripled, does the current increase or decrease and by how | |

| |much? | |

| |6. If the voltage across a fixed-value resistor is cut in | |

| |half, how much will the current change? | |

| |7. There is a fixed voltage across a resistor and you | |

| |measure the current at 1A. If you replace the resistor | |

| |with one that has twice the resistance value, how much | |

| |current will you measure? | |

| |8. In a circuit the voltage is doubled and resistance cut | |

| |in half. Would the current increase or decrease and by how| |

| |much? | |

| |9.In a circuit, v=2, and I = 10 mA. If it is changed to | |

| |1V, what will I be equal to? | |

| |10. If I=3 at a certain voltage, what will it be if the | |

| |voltage is doubled? | |

|Section |Question(Calculate I and show working out) |Response |

|3-2 |1. V=10V, R= 5.6Ω | |

| |2. V=100V, R= 560Ω | |

| |3. V=5V, R= 2.2Ω | |

| |4. V=15V, R= 4.7MΩ | |

| |5. If a 4.7MΩ resistor has 20kV across it, how much | |

| |current is there? | |

| |6. How much current will 10kV across a 2.2Ω resistor | |

| |produce? | |

|Section |Question(Calculate V and show working out) |Response |

|3-3 |1. I =1A & R = 10 Ω | |

| |2. I =8A & R = 470 Ω | |

| |3. I =3mA & R = 100 Ω | |

| |4. I =25 µA & R = 56 Ω | |

| |5. I =2mA & R = 1.8k Ω | |

| |6. I =5mA & R = 100M Ω | |

| |7. I =10µA & R = 2.2MΩ | |

| |8. How much voltage is required to produce 100mA through a| |

| |4.7kΩ resistor? | |

| |9. How much voltage do you need to cause a 3 mA of current| |

| |in a 3.3 kΩ resistor? | |

|Section |Question(Calculate R and show working out) |Response |

|3-4 |1. V =10V & I = 2.13A | |

| |2. V =270V & I = 10A | |

| |3. V =20kV & I = 5.13A | |

| |4. V =15V & I = 2.68mA | |

| |5. V =5V & I = 2.27µA | |

| |6. You have a resistor across which you measure 25V and | |

| |your ammeter indicates 53.2mA of current. What is the | |

| |resistor’s value in kilohms & ohms | |

|Section |Question |Response |

|3-5 | | |

| |1. Name three steps in the APM approach to troubleshooting| |

| |2. Explain the basic idea of the half splitting technique | |

| |3.Why are voltages easier to measure than currents in a | |

| |circuit? | |

|Gen. Test |Question |Response |

| |1. Ohm’s law states: | |

| |2. When the voltage across a resister is doubled the | |

| |current will? | |

| |3.When 10V are applied across a 20Ω resistor the current | |

| |is? | |

| |4. When there are 10mA of current through a 1.0kΩ resistor| |

| |the voltage across the resistor is? | |

| |5. If 20 V are applied across a resistor and there are | |

| |6.06 mA of current the resistance is? | |

| |6. A current of 250µA through a 4.7kΩ resistor produces a | |

| |voltage drop of? | |

| | | |

| | | |

| | | |

| |7.A resistance of 2.2MΩ is connected across a 1kV source | |

| |The resulting current is approximately? | |

| |8.How much resistance is required to limit the current | |

| |from a 10V battery to a 1mA? | |

| |9.An electric heater draws 2.5 A from a 110 V source. The | |

| |resistance of the heating element is? | |

| |10.The current through a flashing bulb is 20mA and the | |

| |total battery voltage is 4.5V. The resistance of the bulb | |

| |is? | |

Section 4

|Section |Question |Response |

|4-1 |1.Define power | |

| |2 .Write the formula for power in terms of energy and time| |

| |3. Define watt | |

| |4. Express each of the following values of power in the | |

| |most appropriate units a. 68 000W b. 0.005W c.0.000025W | |

| |5. If you use 100W of power for 10h how much energy (in | |

| |kWh) have you used? | |

| |6. Convert 2000 Wh to kilowatt-hours | |

| |7. Convert 360 000 Ws to kilowatt-hours | |

|Section |Question |Response |

|4-2 |1. If there are 10 volts across a resistor and a current | |

| |of 3A through it what is the power dissipated? | |

| |2. How much power does the source in fig 4-3 generate? | |

| |What is the power in the resistor? Are the 2 values the | |

| |same? Why? | |

| |3. If there is a current of 5 A through a 56Ω resistor, | |

| |what is the power dissipated? | |

| |4. How much power is dissipated by a 20 mA through a 4.7kΩ| |

| |resistor? | |

| |5. Five volts are applied to a 10Ω resistor. What is the | |

| |power dissipated? | |

| |6. How much power does a 2.2kΩ resistor with 8 volts | |

| |across it dissipate? | |

|Section |Question |Response |

|4-3 |1. Name 2 important values associated with a resistor | |

| |2. How does the physical size of a resistor determine the | |

| |amount of power that it can handle? | |

| |3. List the standard power ratings of metal-film resistors| |

| |4. A resistor must handle0.3 W . What minimum power rating| |

| |of a metal-film resistor should be used to dissipate the | |

| |energy properly? | |

|Section |Question(Calculate R and show working out) |Response |

|4-4 |1. What is the basic reason for energy conversion in a | |

| |resistor? | |

| |2. What is voltage drop? | |

| |3. What is the polarity of a voltage drop in relation to | |

| |conventional current direction? | |

|Section |Question |Response |

|4-5 | | |

| |1. When a loading device draws an increased amount of | |

| |current from a power supply does this change represent a | |

| |greater or smaller load on the supply? | |

| |2. A power supply produces an output voltage of 10V. If | |

| |the supply provides 0.5 A to a load, what is the power to | |

| |a load? | |

| |3.If a battery has a ampere -hour rating of 100 Ah, how | |

| |long can it provide 5A to a load? | |

| |4. If the battery in Q3 is a 12V device what is its power | |

| |to a load for the specified value of current? | |

| |5. An electronic power supply used in the lab operates | |

| |with an input power of 1W. It can provide an output power | |

| |of 750mW. What is its efficiency ? Determine the power | |

| |loss. | |

|Gen. Test |Question |Response |

| |1. Power can be defined as: | |

| |2. Two hundred joules of energy are consumed in 10 s. The | |

| |power is: | |

| | | |

| | | |

| |3.If it takes 300ms to use 10,000 J of energy, the power | |

| |is: | |

| |4. In 50kW ther are how many W | |

| |5. In 0.045 there are a.500W b. 45mW c. 4 500µW d. | |

| |0.00045MW | |

| |6. For 10V and 50mA, the power is a. 500mW b.0.5W c. 500 | |

| |000µW d. all a.b.c | |

| |7.When a current through a 10kΩ resistor is 10mA, the | |

| |power is: a. 1W b. 10W c. 100mW d.1000µW | |

| |8.A 2.2 kΩ resistor dissipates 0.5W. The current is: | |

| |a. 15.1mA b. 0.227mA c. 1.1 mA d.4.4mA | |

| |9.A 330Ω resistor dissipates 2W. The voltage is: a. 2.57V | |

| |b. 660V c. 6.6V d. 25.7V | |

| | | |

| |10.If you used 500W of power for 24h, you have used: a. | |

| |0.5kWh b. 2400Wh c.1200Wh d.12Wh | |

| |11. How many Watt-hours represent 75 W used for 10 h? | |

| |a.75Wh b.750Wh c.0.75Wh d.7500Wh | |

| |12.A 100Ω resistor must carry a max current of 35mA. Its | |

| |rating should be at least: a. 35W b. 35mW c.123mW d. | |

| |3500mW | |

Section 5

|Section |Question |Response |

|5-1 |1.How are the resistors connected in a series circuit? | |

| |2 .How can you identify a series circuit? | |

| |3. Complete the schematics for the circuits in each part | |

| |of fig 5-6 by connecting each group of resistors in series| |

| |in numerical order from terminal a to terminal b | |

| |4. Connect each group of series resistors in fig. 5-6 in | |

| |series with each other | |

|Section |Question |Response |

|5-2 |1. In a circuit with a 10Ω resistor and a 4.7Ω resistor in| |

| |series, there is 1A current through the 10Ω resistor. How | |

| |much current is through the 4.7Ω resistor? | |

| |2. A Milliammeter is connected between points a and b in | |

| |fig. 5-9. It measures 50mA. If you move the meter and | |

| |connect it between points c and d, how much current will | |

| |it indicate? Between e and f? | |

| |3. In fig. 5-10, how much current does ammeter 1 indicate?| |

| |How much current does ammeter 2 indicate? | |

| |4. Describe current in a series circuit | |

|Section |Question |Response |

| |1.The following resistors are in series; 1.0, 2.2, 3.3, | |

| |4.7(all Ω) What is the total resistance? | |

| | | |

| |2. The following resistors are in series; 1x100Ω, 2x56Ω, | |

| |4x12Ω, 1x330Ω. What is the total resistance? | |

| |3. You have one resistor each of the following values; | |

| |1.0k, 2.7k, 5.6k, 560k (all Ω). To get a total resistance | |

| |of approximately 13.8 kΩ, you need one more resistor. What| |

| |should its value be? | |

| |4. What is the RT for twelve 56Ω resistors in series? | |

| |5. What is the RT for twenty 5.6kΩ resistors and thirty | |

| |8.2kΩ resistors in series? | |

|Section |Question |Response |

|5-4 |1. A 10V battery is connected across three 100Ω resistors | |

| |in series. What is the current through each resistor? | |

| |2. How much voltage is required to produce 50mA through | |

| |the circuit of fig. 5-22? | |

| |3. How much voltage is dropped across each resistor in | |

| |fig. 5-22 when the current is 50mA | |

| |4. There are four equal value resistors connected in | |

| |series with a 5 volt source. A current of 4.63 mA is | |

| |measured. What is the value of each resistor? | |

|Section |Question |Response |

|5-5 | | |

| |1. Four 1.5V flashlight batteries are connected in series | |

| |plus to minus. What is the total voltage of all four | |

| |cells? | |

| |2. How many 12 V batteries must be connected in series to | |

| |produce 60V? Draw a schematic that shows the battery | |

| |connections. | |

| | | |

| | | |

| |3. The resistive circuit in fig. 2-29is used to bias a | |

| |transistor amplifier. Show how to connect two 15V power | |

| |supplies in order to get 15V across the two resistors. | |

| |4. Determine the total source voltage in each circuit of | |

| |fig. 5-30 | |

| |5. Draw the equivalent single-source circuit for each | |

| |circuit of fig. 5-30 | |

|Section |Question |Response |

|5-6 | | |

| |1. State Kirchhoff’s voltage law in two ways | |

| |2. A 50V source is connected to a series resistive | |

| |circuit. What is the sum of the voltage drops in this | |

| |circuit? | |

| |3. Two equal-value resistors are connected in series | |

| |across a 10V battery. What is the voltage drop across each| |

| |resistor? | |

| |4. In a series circuit with a 25 V source, there are three| |

| |resistors. One voltage drop is 5V, and the other is 10V . | |

| |What is the value of the third voltage drop? | |

| |5. The individual voltage drops in a series are as | |

| |follows; 1V, 3V,5V,8V,7V. What is the total voltage | |

| |applied across the series string? | |

|Section |Question |Response |

|5-7 | | |

| |1. What is a voltage divider? | |

| |2. How many resistors can there be in a series | |

| |voltage-divider circuit? | |

| |3. Write the general formula for voltage dividers | |

| |4. If two series resistors of equal value are connected | |

| |across a 10V sources, how much voltage is there across | |

| |each resistor? | |

| |5. A 47kΩ resistor and an 82kΩ resistor are connected as a| |

| |voltage divider. The source voltage is 100V. Draw the | |

| |circuit and determine the voltage across each of the | |

| |resistors. | |

|Section |Question |Response |

|5-8 | | |

| |1. If you know the power in each resistor in a series | |

| |circuit, how can you find the total power? | |

| |2. The resistors in a series circuit dissipate the | |

| |following powers: 2W, 5W, 1W, and 8W. What is the total | |

| |powering the circuit? | |

| |3. A circuit has a 100Ω, a 330Ω, and a680Ω resistor in | |

| |series. There is a current of 1A through the circuit. What| |

| |is the total power? | |

|Section |Question |Response |

|5-9 | | |

| |1. What is the reference point of a circuit called? | |

| |2. Voltages in a circuit are generally referenced with | |

| |respect to ground (T or F) | |

| |3. The housing or chassis is often used as reference | |

| |ground? (T or F) | |

|Section |Question |Response |

|5-10 | | |

| |1. Define short | |

| |2. Define open | |

| |3. What happens when a series circuit opens? | |

| |4. Name two general ways which an open circuit can occur | |

| |in practice. What may cause a short circuit to occur? | |

| |5. When a resistor fails, it will normally fail open. (T | |

| |or F) | |

| |6.The total voltage across a string series resistors is 24| |

| |V. If one of the resistors is open, how much voltage is | |

| |there across it? How much is there across each of the good| |

| |resistors? | |

| | | |

|Gen. Test |Question |Response |

| |1. Five equal-value resistors are connected in series and | |

| |there is current of 2mA into the first resistor. The | |

| |amount of current out of the second resistor is; | |

| |a. 2mA b. less than 2mA c. greater than 2mA | |

| |2. To measure the current out of the third resistor in a | |

| |circuit of four series resistors, an ammeter can be | |

| |placed; | |

| |A. between the third and fourth b. between the second and | |

| |third c. at the positive terminal of the source d. at any | |

| |point in the circuit | |

| |3. When a third resistor is connected in series with two | |

| |series resistors, the total resistance ; a. remains the | |

| |same b. increases c. decreases d. increases by one third | |

| |4. When one of four series resistors is removed from a | |

| |circuit and the circuit is reconnected , the current ; a. | |

| |decreases by the amount of current through the third | |

| |resistor b. decreases by a quarter c. quadruples d. | |

| |increases | |

| |5. A series circuit consists of three resistors with | |

| |values of; 100Ω, 220Ω, and 330Ω. The total resistance is | |

| |a. less than 100Ω b. the average of the values c. 550Ω d. | |

| |650Ω | |

| |6. A 9V battery is connected across a series combination | |

| |of 68Ω, 33Ω, 100Ω, and 47Ω resistors. The amount of | |

| |current is? A. 36.3mA b. 27.6mA c. 22.3ma d. 363mA | |

| |7.While putting four 1.5V batteries in a flashlight you | |

| |accidentally put one in back to front. The voltage across | |

| |the bulb will be; a. 6V b. 3V c. 4.5V d. 0V? | |

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| |8. If you measure all the voltage drops and the source | |

| |voltage in a series circuit and add them together, taking | |

| |into account the polarities, you will get a result equal | |

| |to; | |

| |a. the source voltage b. the total of the voltage drops c.| |

| |zero d. the total of the source voltage and the voltage | |

| |drops. | |

| |9.There are six resistors in a given series circuit and | |

| |ach resistor has 5V dropped across it. The source voltage | |

| |is; a 5V b. 30V c. dependent on the resistor values d. | |

| |dependent on the current | |

| |10. A series circuit consists a 4.7kΩ, 5.6kΩ and a 10kΩ | |

| |resistor. The resistor that has the most voltage across it| |

| |is; a. 4.7kΩ b. 5.6kΩ c. 10k d. impossible to determine | |

| |from given values | |

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| |11. Which of the following series combinations dissipates | |

| |the most power when connected across a 100V source? a. | |

| |1x100Ω resistor b. 2x100Ω resistor c. 3x100Ω resistor d. | |

| |4x100Ω resistor | |

| |12.The total power in a certain circuit is 1W. each of the| |

| |five equal value series resistors making up the circuit | |

| |dissipates; a. 1W b. 5W c. 0.5W d. 0.2W | |

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