RL Circuit Question.?
Since you did not give us a frequency, then i'm assuming that you are talking DC, not AC. An inductor acts like a straight wire to a DC circuit (it's resistance is practically zero). If a circuit with one resistor has a current of 2.0 amps, then a series DC circuit with TWO such resistors should be 1.0 amps -- all other things being equal. The inductors are essentially zero ohms at a frequency of zero hertz, so they shouldn't affect the circuit at all.
Could someone check my diode questions, they confuse me?
Which of the following describes the diode curve in the reverse direction? A. ratio I/V is high B. It becomes vertical below brewkdown C. It's current is approximately zero below Breakdown. I chose C for this one --------------------------------------... A diode acts like a high resistance when... A. its current is large B. Forward-Biased C. Reverse-Baiased I chose C once again --------------------------------------... Which of the following approximately describes the diode currve above the forward knee? A. It becomes horizontal B. Voltage Changes Rapidly C. Current increases rapidly D. DC resistance increesess. I chose A --------------------------------------... With forward bias the dc resistance decreasess when A. Current increases B. Diode Decreasess C. the raito V/I increases D. the raito I/V decreases. I chose D.
A little confused about RMS values?
My textbook says that the RMS value of a voltage or current source is the value of the DC voltage or current source that you would replace the AC source with to deliver the same average amount of power to a circuit. Does this mean that if I have a 120V AC voltage source connected to a circuit, that to deliver the same amount of power to the circuit using a DC voltage source, that the DC source should be 120/sqrt2 = 84.85V? I guess I'm just kind of confused on the whole RMS thing in general. I understand how the formula to calculate the RMS value is derived, but am confused as to why it's practical.. I would appreciate it if anyone could shed some light on this subject for me!
NPN Common Emitter Circuit. Bias resistor keeps smoking on me! HELP!?
I'm trying to fix a CB Radio, but this bias resistor keeps getting smokey. It's been a few years since I took transistor theory, so I'm a little confused trying to figure this one out. It's an NPN Common Emitter Transistor. The bias resistor on the base starts smoking about 25 seconds after it's been energized. I've replaced it twice already. I think there was a short to ground somewhere in the circuit that caused it to go bad the first time. I think a chassis screw was touching a component. I can't find anything else bad in this thing. Here's the schematic: http://www.cbtricks.com/radios/uniden/pro_520e/520e_print.htm The resistor in question is R48. It's the bias resistor for Final Transistor Q501. I know this is a little vague, but any insight or ideas would be helpful.
Superposition Theorem?!? Need Help Fast!?!?
For the circuit below use the superposition theorem to calculate the current through R2 (IR2). http://i34.tinypic.com/n4bfhy.png I'm not sure what do do with R1. Do I need to do anything with R1 in order to calculate IR2? or did my teacher just put R1 there to confuse me?
Ohm's Law confusion T_T?
let us assume that you have 5 appliances connected in series. The refrigerator has a resistance of 20Ω, the TV set, 10Ω; the radio, 5Ω; the flatiron, 75Ω; and the electric stove, 55Ω. I f the circuit is connected to a direct current of 220V, what is: a. total Resistance in a Circuit.. b. total Current... c. The voltage drop in each appliance. 2. 3 Resistors having Resistances of 15Ω, 25Ω, & 35Ω, respectively are connected in series. a. draw a Circuit Diagram showing the connection. b. find the total Resistance c. How much Current will there be if the resistors are connected with a 60V source?
Inductors in RL Circuits?
Picture: http://img406.imageshack.us/my.php?image=rlcircuitgw0.jpg Description: Clockwise: emf, switch, resistor, inductor Questions: 1. "When switch is immediately closed, current comes out of emf but does not reach the resistor or inductor because current cannot travel instantaneously (it takes time)." Why does the "inductor produce back emf equal in magnitude to battery emf" when there is no current or change in flux (Len'z Law) within the inductor at that moment in time? 3. "After a long time, the rate of change of the current and the inductor emf both approaches zero. The inductor then acts like a wire." I don't get this. I assume after a long time, current from the battery equals opposing current of inductor. If so, wouldn't that just stop all current since both are colliding? How can inductor acts as a wire when no current can go through it since creates opposing current? I hope you understand why I am confused. Thanks for all your help.
What are the best interview questions for an electrical engineer?
Explain RLC circuit?What is electrics traction?How NPN and PNP transistor works?What does a string of resistors in a series will do?What is Zener diode?what is laser diodes?State the difference between generator and alternator?Why AC systems are preferred over DC systems?How can you relate power engineering with electrical engineering?What are the various kind of cables used for transmission?Why back emf used for a dc motor? highlight its significance.What is slip in an induction motor?Explain the application of storage batteries?Apart from the interview questions, you need to practice interviews in some good online platforms. Most of the websites are providing the mock interview, So, You have to select the best tool for practicing. I would like to suggest InterviewBuddy- (Online mock interviews with experts) is that such platform to practice interview in real-time with industry experts in any domain and provide detailed report to analyze your performance and improve your interview skills.
Question about Power supply color code?
If it's a Meanwell LPC-20, then it is a constant-current supply, not a constant-voltage supply, and you should ignore Roger's comments about resistors. Here's a data sheet: http://www.meanwell.com/search/lpc-20/lp... The full model number is important. An LPC-20-350 will force 350mA through your load (the LED) An LPC-20-700 will force 700mA through your load. The LPC-20-350 will maintain a constant 350mA if the load voltage is anywhere between 9-48VDC. For the LPC-20-700, the voltage range is 9-30VDC. It sounds like you have the LPC-20-350 (due to 48VDC max rating). Your LED or load needs to be rated to accept at least 350mA. At 9VDC, this corresponds to 3.15W and at 48VDC, 13W. So the LED or load should be rated between 3.15W and 13W. To answer your questions about the wires: Blue = neutral Brown = line Connect the above two wires to your power source. In the US, the colors would be white and black, respectively. Use the Blue and Brown as if they were White and Black. There is no ground wire since the case is plastic and the item is UL recognized for a two-wire hookup (to power). The Red and Black connect to the load, and are + and -, respectively. This link shows how to connect the LPC-20 to a 2-wire plug. The site appears to load slowly, but does have many explanatory photos, so it could be worth the wait: http://reefledlights.com/how-to-diy-led/