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because a coil is an inductor,for current leads voltage in an inductor
AnswerIt doesn't! Current lags voltage in a coil. In a purely-inductive circuit, the current lags the supply voltage by 90 degrees. The reason for this is 'self inductance'. Whenever a current changes, a voltage is induced into the coil which opposes that change in current. The maximum self-induced voltage occurs when the rate of change in current is greatest. The greatest positive rate of change of a.c. current occurs when that current is passing through the zero axis of its waveform, so the greatest (negative) induced voltage occurs at thatsame point, which is one-quarter of the wavelength, or 90 degrees. In accordance with Kirchhoff's Voltage Law, the supply voltage must be in antiphase with the induced voltage. So when the peak induced voltage is negative, the peak applied voltage must be positive. Or, to put it another way, the peak value of the applied voltage must occur 90 degrees before the peak value of the current -so the current lags the applied voltage by 90 degrees.
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AC circuit that contains both resistance and inductance will have a.The current and voltage in phase b.current will lead the voltage c.current will lag the voltage d.voltage will lag the current?
a. the current and voltage in phase
What is the emf induced at zero field current.and what does it signify?
EMF is the voltage across a coil (or motor) due to changes in the magnetic field. If you change the current the coil will generate a voltage (in the opposite direction of the current). So it is not the field but the change that matters.
Why voltage leads current in a inductor?
Eli the ice man. Voltage (E) before Current (I) in a coil (inductor)(L) Current (I) before Voltage (E) in a Cap. (C) Got it?
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 diodes protect the circuit from back emf which is generated by relay coils?
The relay coil is an inductor and, as such, resists a change in current. When you de-energize the coil, it attempts to maintain the current flow, but it cannot because you have opened the circuit. This causes a high voltage spike to be developed across the coil which is of opposite polarity to the normal current. The diode conducts, dissipating the current and preventing the voltage from exceeding the safe operating voltage of the driving circuit, often a transistor. The Diode is wired so that it is in reverse during normal operation, so no current passes through the diode and does not affect the coil it is parallel connected to.
What is current coil and voltage coil?
The current coil is one through which the current of source can pass. This coil is connected in series. The voltage coil is connected parallel to the applied voltage. In the current coil the quantity of current flowing is proportional to the current flowing in load while in the voltage coil, current flowing is proportional to applied supply voltage. The voltage coil current is independent of current flow in load. For a complete understanding, please refer to a watt meter diagram.
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.
What is the highest and lowest voltage of an electromagnet?
The strength of an electromagnetic is determined completely by the current through its coil, and doesn't depend on the voltage across the coil. The voltage will be (current) x (resistance of the coil).
What are the reasons why a current is induced in a coil?
Current is not induced into a coil. It's voltage that is induced into a coil. If the coil is connected to a load, or even short circuited, then a current will flow as a result of the induced voltage -but it's the voltage, not the resulting current, that's induced!Voltage is induced into a coil because the the changing magnetic field, due to the change in current (0 to Imax or vice versa) applied to that coil. The process is called 'self induction'.
Why is there a difference in current in a coil when you apply dc voltage and then AC voltage to it?
A coil has both resistance and inductance. When you apply a d.c. voltage, the opposition to current is the resistance of the coil. When you apply an a.c. voltage, the opposition to current is impedance -the vector-sum of the coil's resistance and its inductive reactance. Inductive reactance is proportional to the inductance of the coil and the frequency of the supply.
Is flow of induced current necessary when induces emf is being produced?
There is no such thing as an 'induced current'. Voltages are induced, not currents. If a voltage is self-induced into a coil, then that voltage will oppose any change in current. If a voltage is mutually-induced into a separate coil, no current will flow unless that coil is connected to a load.
Is flow of induce current necessary when induce emf is being produce?
There is no such thing as an 'induced current'. Voltages are induced, not currents. If a voltage is self-induced into a coil, then that voltage will oppose any change in current. If a voltage is mutually-induced into a separate coil, no current will flow unless that coil is connected to a load.
Do you add electrical supply voltage and induced voltage of a coil to get total voltage on the coil?
The induced voltage acts to oppose any change in current that is causing it. So, if the current is increasing, then the induced voltage will act in the opposite direction to the supply voltage; if the current is decreasing, then the induced voltage will act in the same direction as the supply voltage.
What could cause voltage in a coil that has no current running through it?
A: A coil does store energy and this energy will be released after the current is removed is evident by a reversal of voltage across it before it collapse finally with less and less voltage <<>> Using a volt meter to ground, you would see the supply potential coil voltage on the coil end, if the return wire from the coil was open.
What voltage should be applied to make an electromagnet?
The strength of the electromagnet depends on the magnitude of the current in the coil around it.The voltage required is only what produces the desired current in the coil. Since the coil is nothing butwire, the resistance is quite low, and a relatively small voltage produces a relatively large current.
How do you connect energy meter in circuit?
pressure coil or voltage coil across the supply and the current coil in series.
If alternating current is impressed on one coil what will be the frequency of the induced voltage in another coil with which it is coupled?
Same frequency as that of primary coil
