Electric Circuits Answers

1. A basic LED driver circuit is comprised of a 5 volt source a 2 kohm potentiometer and a LED. The LED is forward biased. The LED manufacturer indicates a maximum current rating of 20 mA at a diode voltage drop of 1.9 volts.

a.) What is the minimum value of resistance the potentiometer can be adjusted to before damage to the LED occurs?
b.) What is the nominal resistance of the LED with this condition?
c.) Draw a schematic diagram illustrating the addition of a component that will protect the LED in the event that the pot is adjusted below a safe level.

A solenoidal coil with 30 turns of wire is wound tightly around another coil with 340 turns. The inner solenoid is 21.0 long and has a diameter of 2.50 . At a certain time, the current in the inner solenoid is 0.110 and is increasing at a rate of 1800 . For this time, calculate the average magnetic flux through each turn of the inner solenoid.

A 550-W space heater is designed for operation in Germany, where household electrical outlets supply 230V (rms) service. what is the power output of the heater when plugged into a 120-V (rms) electrical outlet in a house in the united states? ignore the effects of temperature on the heaters resistance.

The brochure advertising a sports car states that the car can be moving at 100.0 km/h, and stop in 37.19 meters. What is its average acceleration during a stop from that velocity? Express your answer in m/s2. Consider the car's initial velocity to be a positive quantity.

prove R=(h2+a2)/2h

what is difference btween convetional and electric current

Ricardo and Jane are standing under a tree in the middle of a pasture. An argument ensues, and they walk away in different directions. Ricardo walks 30.0 in a direction 60.0 west of north. Jane walks 13.0 in a direction 30.0 south of west. They then stop and turn to face each other.

Ok at absolute zero everything stops right but how can a superconductor have persistent current passing through when everything is meant to stop surely the electrons would stop but that defeats the purpose of superconductivty