1 00:00:00,450 --> 00:00:01,830 Hello and welcome. 2 00:00:01,830 --> 00:00:10,940 Today we discuss arms law the most symmetrical relationship E equals I multiple by R. 3 00:00:11,110 --> 00:00:13,930 We must at first doing do the math. 4 00:00:13,930 --> 00:00:18,800 Then we will see cash flow a way to predict Turkish behavior. 5 00:00:18,820 --> 00:00:21,770 It all adds up nothing is lost. 6 00:00:22,840 --> 00:00:24,910 Let's first discuss arms law. 7 00:00:27,560 --> 00:00:27,990 Okay. 8 00:00:27,990 --> 00:00:30,910 As you can see here and arms law. 9 00:00:31,200 --> 00:00:36,220 There is a mathematical relationship between the three components of electricity. 10 00:00:36,270 --> 00:00:46,630 That relationship is arms low E for Volts are for assistance in arms are for currents in arms the mathematical 11 00:00:46,630 --> 00:00:56,950 relationship is E equals I multiple by R we can transform it so R equals E divided by i or i equals 12 00:00:56,980 --> 00:00:58,240 E divided by R 13 00:01:01,260 --> 00:01:06,960 in the following sequence of slides we would be doing exercises where we will set up a circuit using 14 00:01:06,960 --> 00:01:14,580 resistors and voltage sources 9 volt battery predict current using arms low and verify our calculation 15 00:01:15,030 --> 00:01:17,840 by using Volt or meter. 16 00:01:17,950 --> 00:01:30,130 This is the circle of arms low E R E equals I multiply by R R equals E divided by R and R equals E divided 17 00:01:30,130 --> 00:01:31,190 by. 18 00:01:31,450 --> 00:01:35,770 This is a simple way to normalize the low. 19 00:01:35,920 --> 00:01:37,810 Now let's look at this circuit. 20 00:01:37,830 --> 00:01:42,800 This is the basic circuit that you will use for the following exercises. 21 00:01:42,960 --> 00:01:46,910 The volt meter will be moved to measure voltage resistance and current. 22 00:01:47,010 --> 00:01:55,050 As you can see here this is here for current and it's placed here for resolving fault or the stores 23 00:01:56,710 --> 00:02:05,700 uh you must hook up this circuit and you'll ball so that you can keep up with the coming slides while 24 00:02:05,800 --> 00:02:09,710 the circuit using 100 on resistor without power applied. 25 00:02:09,760 --> 00:02:11,960 Measure the resistance of that is a store. 26 00:02:12,190 --> 00:02:16,020 Connect the nine volt battery and measure the Volt across. 27 00:02:16,020 --> 00:02:19,810 There is a store called your data. 28 00:02:19,810 --> 00:02:26,040 Now let's see using the voltage and resistance that ohms law. 29 00:02:26,070 --> 00:02:28,650 Calculate the anticipated current. 30 00:02:29,800 --> 00:02:38,430 In this example all equals divided by our example that result in a current of boiling 09 arms or 90 31 00:02:38,430 --> 00:02:49,450 billion amps with avoided it by 8 volt by ninety eight point one ohms These are the practical readings 32 00:02:49,480 --> 00:02:51,380 using the Volt o meter. 33 00:02:51,430 --> 00:02:55,020 The result is 90 million. 34 00:02:55,320 --> 00:03:02,420 Now listen sir the Volt o meter and the circuit as indicated in this diagram it must be in series or 35 00:03:02,440 --> 00:03:04,760 the current flow through it. 36 00:03:04,960 --> 00:03:13,090 As you can see here using the appropriate current range measure the actual current in the circuit. 37 00:03:13,090 --> 00:03:17,130 How does the current compare to your predicting using Ohm's Law. 38 00:03:18,580 --> 00:03:20,320 You need to compare the two results. 39 00:03:20,320 --> 00:03:21,970 There won't be. 40 00:03:21,970 --> 00:03:26,130 There will be a slightly different value. 41 00:03:26,130 --> 00:03:39,030 Uh but one uh be that different since uh Ohm's Law is the same as measuring the Volt on meter but there 42 00:03:39,030 --> 00:03:48,700 is some practical uh some practical let's say not that we must take into consideration such as heat 43 00:03:48,700 --> 00:03:52,740 dissipation and cup of loss. 44 00:03:52,780 --> 00:03:55,800 Now let's see the second exercise. 45 00:03:55,820 --> 00:04:03,370 Select one kilo on resistor and calculate the restricted circuit retained for this exercise that you 46 00:04:03,370 --> 00:04:06,550 do not know what the voltage of the battery is. 47 00:04:06,730 --> 00:04:13,880 Measure that assistance with the bow arm were removed and then the current with Bohr and recall all 48 00:04:13,870 --> 00:04:14,180 of that. 49 00:04:14,240 --> 00:04:17,050 So here we don't know the voltage source. 50 00:04:17,170 --> 00:04:24,100 We measure the current and we measure that as a store and using another configuration forms low. 51 00:04:24,100 --> 00:04:28,820 We can get E equals ie multiple by are using the current. 52 00:04:28,830 --> 00:04:30,480 Understand that alarms low. 53 00:04:30,520 --> 00:04:34,110 Let's calculate anticipated voltage. 54 00:04:34,300 --> 00:04:37,000 It will equal nine point seventy three Volt. 55 00:04:37,090 --> 00:04:41,780 This from the practical measurement using the Volt or meter. 56 00:04:41,830 --> 00:04:49,300 Now let's connect the Volt o meter in the circuit as indicated here using the appropriate Walgreens 57 00:04:49,390 --> 00:04:52,820 measure the actual voltage across the resistor here. 58 00:04:54,010 --> 00:04:58,150 How does the current compare to your prediction using Ohm's Law. 59 00:04:58,150 --> 00:05:02,910 It will uh be really uh clause. 60 00:05:03,010 --> 00:05:07,480 It will equalize both 7 Volt and that case. 61 00:05:07,480 --> 00:05:08,490 Um. 62 00:05:08,540 --> 00:05:09,700 Uh. 63 00:05:10,240 --> 00:05:11,040 We measured. 64 00:05:11,200 --> 00:05:18,910 Uh here now when several walls and the image of the value is lined both three vaults which are really 65 00:05:18,910 --> 00:05:19,810 close to each other. 66 00:05:21,500 --> 00:05:28,820 These are quick exercises to give you a thorough understanding of arms low. 67 00:05:28,820 --> 00:05:36,590 Now let's look at this failed exercise this exercise you'll use an unknown with so the first one the 68 00:05:37,220 --> 00:05:38,910 current wasn't known. 69 00:05:38,930 --> 00:05:41,310 The second one the voltage wasn't known. 70 00:05:41,330 --> 00:05:44,660 Now the current that is this store isn't known. 71 00:05:44,690 --> 00:05:47,630 So we need to calculate it using Ohm's Law. 72 00:05:47,630 --> 00:05:55,820 We must first measure the current and then measure the voltage then using Ohm's Law R equals E divided 73 00:05:55,820 --> 00:06:01,590 by I will give us the current that will give us. 74 00:06:01,640 --> 00:06:09,900 Sorry that is the store value which will be three point three thousand eight hundred forty four ohm 75 00:06:10,300 --> 00:06:14,690 or three point a two K low on. 76 00:06:14,750 --> 00:06:20,170 So it's really close to the real value. 77 00:06:20,490 --> 00:06:27,380 The previous three exact exercises we managed to use Ohm's law to get the current value. 78 00:06:27,690 --> 00:06:34,800 The voltage value and the resistance value in each case two of the three components must be known for 79 00:06:34,800 --> 00:06:35,290 that. 80 00:06:35,490 --> 00:06:43,310 So that we can calculate the fair component that is missing. 81 00:06:43,540 --> 00:06:45,850 Now let's look at arm's law and practice 82 00:06:50,240 --> 00:06:59,970 the next series of slides or exercises will both arms low to use to illustrate some principle of basic 83 00:06:59,970 --> 00:07:08,750 electronics as in the previous exercises you will build the circuit and insert the Volt or meter into 84 00:07:08,750 --> 00:07:15,440 the circuit in the appropriate way to make current and voltage measurement throughout the exercises 85 00:07:15,540 --> 00:07:21,090 record your data so that you can compare it to calculations now. 86 00:07:21,260 --> 00:07:30,420 Let's build this circuit these other resistor values series Battle series and the three are Conference 87 00:07:30,470 --> 00:07:31,880 series together. 88 00:07:31,880 --> 00:07:36,210 And here we have a meta. 89 00:07:36,830 --> 00:07:47,930 Now if we look at the circuit and plays first let's measure the current flowing through the circuit 90 00:07:47,930 --> 00:07:55,960 using this meta then move the Volt or meter to the other side of the circuit and measure the current 91 00:07:55,960 --> 00:07:56,940 here. 92 00:07:57,160 --> 00:08:03,040 The current should be the same as the previous measurement since the graph for a flowing through here 93 00:08:03,340 --> 00:08:12,980 is the same that going back here now and said the Volt o meter at the indicated location and measure 94 00:08:12,980 --> 00:08:17,480 of the current year there should be no surprise that the current is the same 95 00:08:20,250 --> 00:08:23,160 four point six five billion arms. 96 00:08:23,220 --> 00:08:32,430 If you are doing this annual bread board this is the reading of the meta Dow measure the voltage across 97 00:08:32,430 --> 00:08:39,570 our line here using OMS low calculate the voltage drop across along on the store are the current EU 98 00:08:39,570 --> 00:08:40,680 measures. 99 00:08:40,920 --> 00:08:49,440 Here we can calculate the voltage drop if we image of the voltage here using the current and that is 100 00:08:49,440 --> 00:08:58,500 a store we can calculate the voltage so using Oslo equals ie multiple by r e e will equal four point 101 00:08:58,500 --> 00:09:05,750 sixty five volt as you can see here the value is for Boyne 102 00:09:08,550 --> 00:09:11,460 okay four point six five vol. 103 00:09:11,880 --> 00:09:20,560 This is the calculated value and the voltage on the test bed using the volt meter was four point six. 104 00:09:20,910 --> 00:09:22,280 There is no 6 5. 105 00:09:22,290 --> 00:09:27,180 So this is a very small difference between the two circuits. 106 00:09:27,180 --> 00:09:34,290 Now in the next step you will insert the Volt o meter in the circuit at two places illustrated at 1 107 00:09:34,410 --> 00:09:42,810 and 2 here until you record your current readings for both places at the current and compare and contrast 108 00:09:43,410 --> 00:09:46,200 to the current child entering the total circuit. 109 00:09:46,650 --> 00:09:52,730 So if we add these two columns there must equal the main current or the main source of column 110 00:09:56,270 --> 00:10:04,910 now using the current meter throw number one and the resistance value of r to one get along calculate 111 00:10:04,910 --> 00:10:08,310 the voltage drawbacks or accrual across that resistor. 112 00:10:09,680 --> 00:10:12,100 Likewise do the same with the current method. 113 00:10:12,130 --> 00:10:19,520 Throw number 2 and the resistance value of our 3 2 point to create a long compare and contrast these 114 00:10:19,520 --> 00:10:24,760 two values of voltage values uh as you can see in number 1. 115 00:10:24,980 --> 00:10:28,900 Uh the value will be three point two one vote. 116 00:10:29,270 --> 00:10:34,020 And number two the value will be three point 1 6 8 vote. 117 00:10:34,100 --> 00:10:37,740 The value are essentially the same and they should be. 118 00:10:37,740 --> 00:10:46,920 Since the voltage is the same in battle as you can see the voters here must be equal. 119 00:10:46,910 --> 00:10:51,320 The voltage here measure the voltage across the battery with the store and record your answer. 120 00:10:51,320 --> 00:10:57,230 Compare and contrast the voltage measure to the voltage drop calculated the measure of the value will 121 00:10:57,230 --> 00:11:04,690 be three point one seven and that is bad and you can see that there is a very small difference but they 122 00:11:04,690 --> 00:11:07,710 are basically the same values. 123 00:11:07,930 --> 00:11:16,630 Now uh if we looked at this example this said the Volt o meter into the circuit here let's compare and 124 00:11:16,630 --> 00:11:18,270 contrast the results. 125 00:11:18,370 --> 00:11:29,060 It will measure four point six million arms and if we did measure the volunteer uh using the current 126 00:11:29,330 --> 00:11:35,000 you just miss out under the results of our four calculate what the voltage drop across our force would 127 00:11:35,000 --> 00:11:43,910 be to equal one point five to volt listen sell the Volt o meter into the circuit as alleged rated and 128 00:11:43,910 --> 00:11:45,330 measure the voltage. 129 00:11:45,350 --> 00:11:52,220 This is the practical value to compare and contrast the middle damage out and calculated voltage it 130 00:11:52,220 --> 00:11:55,360 will equal one point five six. 131 00:11:55,400 --> 00:11:58,510 They are basically the same. 132 00:11:59,000 --> 00:12:06,690 Um this is one final measurement to complete this portion of the exercise and the Volt o meter indicated 133 00:12:06,690 --> 00:12:14,380 here because the three voltages Mitchell previously across are 1 2 3 and 4. 134 00:12:14,720 --> 00:12:21,510 Add these three voltage together and then compare and contrast the result with the total vultures just 135 00:12:21,510 --> 00:12:21,770 measured. 136 00:12:21,930 --> 00:12:35,190 So throw out one was four point six R1 3 it was three point one 7 while an order for it was one point 137 00:12:35,190 --> 00:12:37,200 five six. 138 00:12:37,350 --> 00:12:41,310 The total output voltage was three boring. 139 00:12:43,210 --> 00:12:48,570 Or nine point three three. 140 00:12:48,600 --> 00:12:56,180 So what you observed was the sum of the individual counts was equal to the total current flowing through 141 00:12:56,200 --> 00:12:57,620 the circuit. 142 00:12:57,810 --> 00:13:03,070 The sum of the voltage drops was equal to the total voltage across the circuit. 143 00:13:03,960 --> 00:13:08,550 This is cash flow and is very useful in the study of electronic circuit. 144 00:13:08,550 --> 00:13:14,110 You also note noted that Ohm's Law applied throughout the circuit. 145 00:13:14,430 --> 00:13:16,770 Uh that's it for Ohm's Law. 146 00:13:16,770 --> 00:13:24,750 I know that I did it really quick but I will applaud that slide so that you can grow each of these exercise 147 00:13:25,290 --> 00:13:29,020 one by one and apply them in your test bed. 148 00:13:30,440 --> 00:13:36,170 This is basically a really simple laundry list but you need to understand it correctly. 149 00:13:36,190 --> 00:13:37,570 Thanks for watching. 150 00:13:37,690 --> 00:13:42,330 And next we will explain to our stores this is education engineering team.