bluemoon Posted May 10, 2006 Report Share Posted May 10, 2006 An Electric DC Circuit is attached to a 12-volt batter and has a 3-ohm resistor in it. Find the current flowing through the circuit What is the current in an AC Circuit with 120 volts and a 60 watt light bulb? I wasn't very good at circuits at all. Help please? Quote Link to comment Share on other sites More sharing options...

Turtle Posted May 10, 2006 Report Share Posted May 10, 2006 An Electric DC Circuit is attached to a 12-volt batter and has a 3-ohm resistor in it. Find the current flowing through the circuit What is the current in an AC Circuit with 120 volts and a 60 watt light bulb? I wasn't very good at circuits at all. Help please? What you need is Ohms Law & some elbow grease.:hihi: http://jersey.uoregon.edu/vlab/Voltage/:shrug: Quote Link to comment Share on other sites More sharing options...

ronthepon Posted May 10, 2006 Report Share Posted May 10, 2006 I understand your problem, bluemoon, we are very close by on the academic ladder. I'm telling you all this because even I wanna revise Ohm's law is like:V=IR V is the potential difference across the resistorI is the current flowing through th resistorR is the resistance. So lets solve your first question An Electric DC Circuit is attached to a 12-volt batter and has a 3-ohm resistor in it.Find the current flowing through the circuit V= 12 VoltsR= 3 Ohms So 12=(I)3 giving I= 4 Amperes Now your second one What is the current in an AC Circuit with 120 volts and a 60 watt light bulb? Remember that the bulb is using 60 watts when you supply 120 volts.Soits using 60 Joules used per second. Use the equations: P=(V^2)/R(means V squared divided by R) and P=(I^2)RThe symbols have the usual significance. So, P=60 Joules per secondV= 120 Volts We get 60=120*120/RSolving, R=240 Ohms Now we can use this in the second equation I mentioned. 60=(I^2)240 I^2=1/4 I=1/2 = 0.5 Amperes Thats all! So simple for theory. Want a tip to excel in your exams?Won't you bother to read your textbooks to get the concepts? No hope for you if you don't... Quote Link to comment Share on other sites More sharing options...

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