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.
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.
a. the current and voltage in phase
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?
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.
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.
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.
Oh, dude, current coils and voltage coils are just like the Beyoncé and Jay-Z of transformers. The current coil measures the current flowing through a circuit, while the voltage coil measures the voltage across a circuit. They're basically the dynamic duo of electrical measurements, keeping things in check and making sure everything runs smoothly.
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).
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'.
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.
The current flowing through the heating coil will depend on the resistance of the coil and the voltage of the power source. Using Ohm's Law (I = V/R), where I is the current, V is the voltage, and R is the resistance, you can calculate the current. The higher the voltage or lower the resistance, the higher the current.
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.
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.
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.
When the magnet is withdrawn from the coil, the magnetic field within the coil will decrease, inducing a voltage in the coil. This induced voltage will create a current in the coil that flows in such a way as to try to maintain the original magnetic field.
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.
A step-up transformer increases the voltage of an electrical current by having more turns in the secondary coil than in the primary coil. This causes the magnetic field to induce a higher voltage in the secondary coil, resulting in an increase in voltage.