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Would it be correct to say ' with a fixed field voltage the speed of a shunt motor is proportional to its armature voltage?
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Which the effect of the increase of the armature voltage on the speed of a direct-current separately excited motor in case of constant load?
Increasing the armature voltage would increase the speed. In a separately excited dc motor the speed adjusts so that the back emf generated by the armature is a little less than the supply voltage. The difference, divided by the resistance, gives the current drawn, which is also proportional to the shaft torque supplied to the load.
Would it be correct to say with a fixed field voltagethe speed of a shunt motor is proportional to its armature voltage?
With increasing torque load the armature tends to slow down; the motor draws more current to compensate, and if there is armature resistance the back emf generated by the armature falls to allow the increased current to flow, which causes the motor to settle at a lower speed. The mechanical output power is the speed times the torque, and increasing the torque increases the power output provided the speed does not drop much.
What is step up and step down?
Usually refers to a transformer. A step up transformer increases the voltage and a step down decreases the voltage by an amount proportional to the ratio of the windings between Primary and Secondary. A 1:2 ratio is a step up and doubles the voltage. A 2:1 would be a step down and halve the voltage.
You are monitoring electric current in a circuit. you notice the voltage increasing this mean's that?
Ohm's Law states that the current (I) flowing in a circuit is directly proportional to the applied voltage (E) and inversely proportional to the circuit's resistance (R).I = E/RAnother way of stating Ohm's Law is that the applied voltage (E) is directly proportional to both the current (I) and the resistance (R).E = IxR.So, if the voltage (E) is increasing, then either:if you know the resistance (R) is staying constant then the current (I) must be increasing - which you would see because you are monitoring it! or, if the current (which you are monitoring) is actually staying constant, then, for the voltage to be able to increase:the circuit's resistance must be increasing orthe increasing voltage could be caused by a combination of both increasing current and increasing resistance!
What happens to voltage when resistance is increased?
Ohms law is V=I X R. If resistance (R) is reduced and current (I) is constant, then voltage (V) must decrease. You can see from the equation that they are proportional to one another. If, however, R is reduced and V is held constant, then I must increase (I and R are inversely proportional). The only way V can increase is if either or both I and R increase.
Would a DC motor turn if only the armature were supplied DC voltage?
if there are magnets on the stator and the commutator is phased properly this is known as a permanent magnet dc motor the starting torque is dependent on armature current and the strength of the magnet the speed is directly proportional to the armature voltage a shunt motor needs the field energized for starting. more field more starting torque
Which the effect of the increase of the armature voltage on the speed of a direct-current separately excited motor in case of constant load?
Increasing the armature voltage would increase the speed. In a separately excited dc motor the speed adjusts so that the back emf generated by the armature is a little less than the supply voltage. The difference, divided by the resistance, gives the current drawn, which is also proportional to the shaft torque supplied to the load.
Would the motor turn if only the armature were excited?
A motor will turn when only the armature is excited, if there is enough residual magnetism in the field.
Would it be correct to say with a fixed field voltagethe speed of a shunt motor is proportional to its armature voltage?
With increasing torque load the armature tends to slow down; the motor draws more current to compensate, and if there is armature resistance the back emf generated by the armature falls to allow the increased current to flow, which causes the motor to settle at a lower speed. The mechanical output power is the speed times the torque, and increasing the torque increases the power output provided the speed does not drop much.
If you were to mechanically rotate the armature in an electric motor what would happen?
You said "armature" so it is a dc motor. Hence if the field is permanent magnet type then a voltage appears at the armature terminals nd its magnitude depends on the speed nd magnetic field strength. If it's field coils, then they must be seperately excited (if it don't possess residual). By changing the field strength you can vary the voltage produced at armature terminals.
Why is stationary armature preffered you commercial generators than moving armature?
The problem with a generator having a rotating armature is that the armature must be connected to its external load via slip rings and brushes. As power station alternators generate voltages up to 25 kV or so, and supply hundreds of amperes, the resulting arcing at the slip rings would be severe, and would require short maintenance cycles. Accordingly, it makes more sense for the armature to be stationary, and connected directly to its load, and have the field winding rotate instead, because the voltage/current applied to the field winding is quite low.
Why do inversely proportional functions have asymptotes?
Because the two variables cannot be zero voltage = current*resistance if we draw graph current against resistance we would see a exponential graph which means the two variables are inversely proportional but either cannot be zero because voltage is not equal to 0 n.j.p
If a generator is rated at 441 watts at 5000 rpm What would watts be at 2000 rpm?
If it's a dc generator it would produce 2/5 of the voltage at the lower speed, and another factor of 2/5 less if the armature supplies the field winding. So the voltage output could be 16% of the rated voltage. The current limit would be the same, so the output would be 71 watts maximum.
What is step up and step down?
Usually refers to a transformer. A step up transformer increases the voltage and a step down decreases the voltage by an amount proportional to the ratio of the windings between Primary and Secondary. A 1:2 ratio is a step up and doubles the voltage. A 2:1 would be a step down and halve the voltage.
When voltage increases what happens to current?
Ohm's law states that "The current is directly proportional to the applied EMF (voltage) and inversely proportional to the resistance in the circuit."AnswerIf the voltage across a circuit increases, then the current will increase too. If the ratio of voltage to current is constant for variations in voltage, then the circuit is described as being 'linear' and is obeying Ohm's Law; if the ratio of voltage to current changes (as it would, for example, with tungsten) for variations in voltage, then the circuit is described as being 'non-linear', and is not obeying Ohm's Law. This is because Ohm's Law is not universal, and only applies to certain materials; in fact, most materials and electronic devices do not obey Ohm's Law.
Actually if voltage is fedback naturally current willalso be fedback to the input circuit But how can it be NT proportional?
Yes, since voltage is fed back to the input circuit, current will also be fed back but, no, it will not be exponential since current is linearly proportional to voltage when resistance is constant.Ohm's law: Current equals voltage divided by resistance.In any case, it would not matter, because your feedback loop is balancing like for like. If you use a voltage basis, then the input is also voltage - and current similarly balances current.This answer assumes that the questioner is talking about an op-amp. If this is incorrect, please reply to the answerer and I will attempt to answer as appropriate.
You are monitoring electric current in a circuit. you notice the voltage increasing this mean's that?
Ohm's Law states that the current (I) flowing in a circuit is directly proportional to the applied voltage (E) and inversely proportional to the circuit's resistance (R).I = E/RAnother way of stating Ohm's Law is that the applied voltage (E) is directly proportional to both the current (I) and the resistance (R).E = IxR.So, if the voltage (E) is increasing, then either:if you know the resistance (R) is staying constant then the current (I) must be increasing - which you would see because you are monitoring it! or, if the current (which you are monitoring) is actually staying constant, then, for the voltage to be able to increase:the circuit's resistance must be increasing orthe increasing voltage could be caused by a combination of both increasing current and increasing resistance!
