0
Can a watt meter that has current through its current coil and a potential across its voltage coil indicate zero?
Mshabba
A watt meter that has current through its current coil and voltage across its voltage coil will indicate zero if the power factor between the volts and amps is zero. This condition would be one in which the current will either lead or lag the voltage by 90 degrees and the circuit will have amps, volts, VARS, and VA, but will not have Watts.
Wiki User
∙ 14y ago
Wiki User
∙ 12y agoYes, if the current is at 90 degrees phase angle with respect to voltage, the wattmeter will indicate zero, because power factor under those conditions is zero.
Think about it this way. During part of the line cycle, current flows with the voltage and, during part of the line cycle, current flows against the voltage. This "anti-flow" constitutes "negative" power. Averaging out the pluses and minuses, you get zero. In fact, it should come as no surprise to find that, if you increase the phase angle beyond 90 degrees, the wattmeter will actually run backwards, and that is representative of the true state of affairs - a power factor less than one means you have a generator instead of a motor.
Add your answer:
Earn +20 pts
When the current traveling through a resistor is increased what happens to the voltage that travels through the same resistor?
Your question reveals fundamental misunderstandings about the nature of electricity.'Voltage' is simply another word for 'potential difference', and a potential difference appears across opposite ends of the resistor; it doesn't 'travel through' that resistor! Current, on the other hand, DOES 'travel through' the resistor and is caused by the potential difference across the resistor.Resistance is the ratio of potential difference to current. So if the resistance remians unchanged when the current through it doubles, then it has happened because the potential difference has doubled.
What came first the voltage or the current?
For a current to flow between two points, those points must have a potential difference (voltage) across them.
What is the potential difference neede to send 2a through a 5 ohms resistor?
V=I*R -- Potential (Voltage, V) = Current (Amperage, I) * Resistance (Ohms)2A*5Ohms = 10V
8 If the resistance of an electric circuit is 12 ohms and the voltage in the circuit is 60 V the current flowing through the circuit is?
There is a simple equation relating voltage (properly potential difference), current and resistance: V=IR Where V=potential difference, I=current and R=resistance So to answer: I=60/12 I=5
What is voltage drop in an electrical circuit?
When a current flow on a conductor , or load or resistor, some voltage will drop across that load or resistor.AnswerA voltage drop is the potential difference appearing across individual components in a circuit, necessary to drive current through those components. The sum of the individual voltage drops around a series circuit will equal the supply voltage applied to that circuit.
Can a wattmeter that has a current through its current coil and a potential across its voltage indicate zero?
A: Only if the current is very small and the scaling very large. Like trying to measure micro amps on amp meter
Would it be true to say that current causes voltage?
Volts = Current x Resistance. The voltage is where the potential resides for the amount of current flowing through a resistance. Think about the voltage as a potential source of electrons that then flow through a circuit depending on the Load, or resistance in this example.
When the current traveling through a resistor is increased what happens to the voltage that travels through the same resistor?
Your question reveals fundamental misunderstandings about the nature of electricity.'Voltage' is simply another word for 'potential difference', and a potential difference appears across opposite ends of the resistor; it doesn't 'travel through' that resistor! Current, on the other hand, DOES 'travel through' the resistor and is caused by the potential difference across the resistor.Resistance is the ratio of potential difference to current. So if the resistance remians unchanged when the current through it doubles, then it has happened because the potential difference has doubled.
What device uses the voltage in an electrical current?
A voltage, or potential difference, is what causes current to flow through a circuit. So all devices (called 'loads') require a voltage applied to them.
How much current flows through a resistor with zero potential difference?
No current flows when the the voltage is zero.
What is the difference between voltage ang current?
voltage: it is the potentail difference between two wires. or it is the amount of energy used to force the electrons.current: it is the flow of free electrons.by Balaji,NITCAnswerThere is no such expression as 'potential voltage'. 'Voltage' is simply another word for 'potential difference'.
How can you determine the resistance of a current?
Voltage = Current x Resistance giving us Current = Voltage / Resistance i.e. Voltage divided by resistance
One way to make current is to use a what?
You can apply a potential difference across a wire to cause a current to flow through. Ohm's Law allows you to calculate the amount of current based on the voltage supplied and the resistance of the circuit. I = current V = voltage or potential difference R = resistance I = V/R
Why do you have voltage on open circuit?
Voltage is simply electrical potential. You do not have to have current to have voltage, but you have to have both voltage and current in order to have power transfer.Voltage = joules per coulombCurrent = coulombs per secondWatts = Voltage times current = joules per secondAnswer'Voltage' is a synonym for 'potential difference', not potential. A potential difference exists between two points which are at different potentials due to an imbalance of their electrical charges.
Why current lag and potemtial lead in an inductor.?
because of flux produced in coil of inducterAnswerThe potential difference (not 'potential') induced into a pure inductive component is proportional to the rate of change of current. The greatest rate of change of current occurs when the current waveform passes through zero (i.e. is at its steepest angle). So the voltage is maximum when the current is passing through zero -which means that the current is lagging the voltage by 90 degrees.
How does voltage produce current?
Voltage across two terminals mean there exists a potential difference, and when the circuit gets closed, due to this potential difference the current flow.
What is the difference between current coil and voltage coil?
These terms apply to the coils inside a wattmeter. 'Pressure coil' is an archaic term for 'voltage coil', which is connected in parallel with the supply, while the 'current coil' is connected in series with the load.
