- All other factors being equal, greater coil area (as measured looking lengthwise through the coil, at the cross-section of the core) results in greater inductance; less coil area results in less inductance
- When the coil turns are increased, the _____. It causes the overcurrent protection to open. d. It reduces the current. It reduces the current. All of the following factors increase the inductance of a coil, except a: a. greater number of turns b. longer core c. wider coil d. magnetic core
- The inductance of a coil can be increased by placing a magnetic core of ferromagnetic material in the hole in the center. The magnetic field of the coil magnetizes the material of the core, aligning its magnetic domains , and the magnetic field of the core adds to that of the coil, increasing the flux through the coil
- 49. A coil with a self-inductance of 6.5 H carries a current that is changing at a rate of 50 sudden decrease in its rotational frequency causes A) an increased back emf and an increased current flow. may increase or decrease depending on the magnitude of the original frequency. D) may increase or decrease depending on the magnitude of.
- Of the items listed below, which affects the inductance of a coil? Decrease the spacing between the windings. Which of the following will increase the inductance of a coil? It is an opposing force to the applied voltage which resists changes in circuit current
- The purpose of a discharge resistor across a dc relay coil is to: A) reduce high voltage spikes due to coil flux collapse B) allow the relay to pick up faster C) provide a short delay in the pick-up D) offset the inductance of the coil E) take care of more than one of the abov

The inductance of a coil will increase under all the following conditions except A. When more length for the same number of turns is provided. B. When the number of turns of the coil increase. C. When more area for each turn is provided. D. When permeability of the core increases. Answer: Option B. inductive reactance of the coil decreases. C. inductance of the coil decreases. D. resistance of the coil decreases. A. test frequency increases. 4. When a metal part is placed in an Eddy current test coil, the impedance of the coil will be changed by all of the following properties of the part except: A. conductivity. B. dimensions The inductance of a coil can be increased by A. Increasing core length. B. Decreasing the number of turns. C. Decreasing the diameter of the former. D. Choosing core material having high relative permeability. Answer: Option 18. Which of the following factors will NOT affect the value of inductance of a coil? A. Number of coil turns; B. Diameter of the coil; C. Conductor tensility; D. Core materials used; 19. When the number of turns is increased in a coil from 2 to 4, the total inductance will increase by a factor of. A. eight; B. two; C. six; D. four; 20

8. State whether the inductive reactance (increases or decrease) with each of the following changes: a. Increase in the frequency of the AC supply source. Increase. b. Decrease in the inductance of the coil. Decrease. The above results are based on the following formula: ${{X}_{L}}=2\pi fL$ 9 Question is ⇒ In an iron cored coil the iron core is removed so that the coil becomes an air cored coil. The inductance of the coil will, Options are ⇒ (A) increase, (B) decrease, (C) remain the same, (D) initially increase and then decrease, (E) , Leave your comments or Download question paper

When number of turns in coil is decreased, the self inductance will decrease. (ii) When an iron rod is introduced in the coil, the self-inductance of coil increases. Answered by | 7th Jul, 2015, 04:20: PM. Concept Videos. This video explains mutual inductance. This video explains mutual inductance Self-inductance, the effect of Faraday's law of induction of a device on itself, also exists. When, for example, current through a coil is increased, the magnetic field and flux also increase, inducing a counter emf, as required by Lenz's law. Conversely, if the current is decreased, an emf is induced that opposes the decrease

Earlier NEETS modules state that the **inductance** **of** **a** **coil** increases directly as the permeability of the core material increases. If a **coil** is wound around an iron core, the permeability of the core is 5000. Now, if the iron is pulled part way out of the **coil** **of** wire, the core is part iron and part air. The permeability of the core **decreases** Stretching the coil, to space the same number of turns over a longer length, would reduce the inductance (you could think of it as magnetic field leaking out of the coil and not linking with so many turns). Note the 40l in the denominator of L : Units for L depend on the units used for lengths The inductance (or more precisely, the self-inductance) of the coil can be found using the following equation: Applied Formula in Electrical Circuits: Review of the Inductance Process To understand the inductance process and how it works let's review the illustrated DC supply with a switch and a coil (figure 1). When the switch is closed.

If the coil has some internal resistance then we need to represent the total impedance of the coil as a resistance in series with an inductance and in an AC circuit that contains both inductance, L and resistance, R the voltage, V across the combination will be the phasor sum of the two component voltages, V R and V L The inductance of the coil carrying a constant D.C. current will not affect the current The inductance of the coil carrying a constant D.C. current will decrease the current ⇒ A coil is wound on iron core which carries current I. The self induced voltage in the coil is not affected by variation in coil current variation in voltage to the coil

The magnetization of the core material interacts with the magnetic field of the windings and changes the inductance. The core magnetization has hysteresis and this affect the core magnetization and combined magnetization. The inductance changes non-linearly and the hysteresis gives odd effects too In case of Inductive circuit: Z = √ (R 2 + X L 2); I = V / X L or I = V / Z; It shows that in inductive circuit, Current is inversely proportional to the inductive reactance as well as inductance L as inductance and inductive reactances X L are directly proportional to each others.. Related Question: According to Ohm's Law, I ∝ V, But I ∝ 1/V in Power Equation

(i) Mutual inductance decreases. (ii) Mutual inductance increases. Concept (i) If distance two coils is increased as shown in figure. If causes decrease in magnetic flux linked with the coil C 2 .Hence induced emf in coil C

** Inductance is not only associated with coils of wire**. Anything with current flowing through it will create a magnetic field and will therefore have an inductance. Of course, if there is no coil, then the number of turns N will always be equal to 1. Example 15.3: Determine the inductance of the following coaxial cable. Current flows ou Inductance and Magnetic Energy 11.1 Mutual Inductance Suppose two coils are placed near each other, as shown in Figure 11.1.1 Figure 11.1.1 Changing current in coil 1 produces changing magnetic flux in coil 2. The first coil has N1 turns and carries a current I1 which gives rise to a magnetic field B1 5 C-C Tsai 9 Air-Core Inductors All flux lines do not pass through all of the windings Flux is directly proportional to current Induced voltage directly proportional to rate of change of current C-C Tsai 10 Self-Inductance Voltage induced in a coil is proportional to rate of change of the current Proportionality constant is L Self-inductance of the coil-units are Henrys (H Long gap between the turns means more lengthy coil and it means less inductance. On the other hand if you fix the length then long gap means less number of turns and it cause to decrease the.

Electrical Engineering Q&A Library What effect (increase or decrease) would the following changes have on the inductance of a coil? (Justify your answer) Increasein the number of turns of wire Removal of its iron cor As with mutual inductance, the induced emf is proportional to the change in current. The induced emf can be written as: The constant L is known as the inductance of the coil. It depends on the coil geometry, as well as on whether the coil has a core of ferromagnetic material 28. When the current in one coil changes at a rate of 5.6 A/s, an emf of is induced in a second, nearby coil. What is the mutual inductance of the two coils? Solution . 29. An emf of is induced in a coil while the current in a nearby coil is decreasing at a rate of 2.7 A/s. What is the mutual inductance of the two coils? Solution 30 4. The inductance of a coil will increase under all the following conditions except (a) when more length for the same number of turns is provided (6) when the number of turns of the coil increase (c) when more area for each turn is provided (d) when permeability of the core increases Ans: a. 5. Higher the self-inductance of a coil, (a) lesser.

The inductance of a coil will increase under all the following conditions except (a) when more length for the same number of turns is provided (6) when the number of turns of the coil increase (c) when more area for each turn is provided (d) when permeability of the core increases. Ans: a. Higher the self-inductance of a coil, (a) lesser its. on a coil of 624 turns and 6.121 inches diameter. The inductance is now 17,670 µH, larger but still less than that of the copper coil. The aluminum coil has more resistance and less inductance than the copper coil, both undesirable. As a side issue, if we hold the winding length ﬁxed, the coil gets to be relatively short and fat

The inductance (L) of a coil and the time rate of change of the current (di/dt) determine the induced voltage (V ind). A change in current causes a change in the electromagnetic field, which, in turn, induces a voltage across the coil, as you know. the induced voltage is directly proportional to L and di/dt, as stated by the following formula L is the inductance in henries. d is the diameter of the coil in metres. n is the number of turns in the coil. l is the length of the coil in metres. For coils not conforming exactly to the above specification extra factors must be incorporated. Fig. 3.2.1 illustrates one way of producing a sufficiently accurate inductance, used in some HF and. (i) When the distance between a pair of coils is increased, the magnetic flux linked with the secondary coil decreases and hence, the mutual inductance between them will decrease. (ii) Since M ∝ N 1 N 2, so, when number of turns in the coil is increased, the mutual inductance will also increase ** 3**.COIL LENGTH: All other factors being equal, the longer the coil's length, the less inductance; the shorter the coil's length, the greater the inductance. Explanation: A longer path for the magnetic field flux to take results in more opposition to the formation of that flux for any given amount of field force (amp-turns)

- 1. Mutual Inductance - A changing current in coil 1 causes B and a changing magnetic flux through coil 2 that induces emf in coil 2. dt d N B2 2 2 Φ ε = − N2ΦB2 = M21 i1 1 2 2 21 1 2 21 i N M dt di M B Φ ε = − → = dt di M dt d N B 1 21 2 2 = Φ Magnetic flux through coil 2: Mutual inductance of two coils: M 21 M21 is a constant that.
- Self - Inductance ÎConsider a single isolated coil: Current (red) starts to flow clockwise due to the battery But the buildup of current leads to changing flux in loop Induced emf (green) opposes the change ddi NL dt dt ε Φ =− =− L is the self-inductance units = Henry (H) induced emf This is a self-induced emf (also called back.
- i) In the case of self - inductance:- It is defined as the ratio of average emf in the coil to the time rate of change of current in the same coil. ii) In the case of Mutual inductance:- It is defined as the mutual inductance of the pair of coil in which a rate of change of current of one ampere per second in the primary causes an induced emf.
- Self-inductance: Self-inductance is the property of a circuit, often a coil, whereby a change in current causes a change in voltage in that circuit due to the magnetic effect of caused by the current flow. It can be seen that self-inductance applies to a single circuit - in other words it is an inductance, typically within a single coil

When two or more inductors are connected in series, then the inductance of one inductor will be affected by the magnetic field produced by the other coil. This is called mutual inductance and the coils are called Mutually connected inductors. This mutual inductance may increase or decrease the total inductance of the series circuit Since the area is a function of the square of the diameter of the coil, inductance increases as the square of the diameter. (d) Inductance decreases as the length l of the coil increases (assuming the number of turns remains the constant) Inductors in Series and Parallel Connection Inductance adds when inductors are connected in series

- For example, the parasitic self inductance of a wire wound resistor is quite large due the resistance element being realized by a coil of wire. The parasitic capacitance will also be quite large.
- Mutual inductance may be defined as the ability of one coil or circuit to induce an emf in a nearby coil by induction when the current flowing in the first coil is changed. The action is also reciprocal i.e. the change in current flowing through second coil will also induce an emf in the first coil
- 1. If we change the magnetic flux through a
**coil****of**N turns, an induced emf appears in every turn and the total emf induced in the**coil**is the sum of these individual induced emfs. If the**coil**is tightly wound (closely packed), so that the same magnetic flux B passes through all the turns, the total emf induced in the**coil**is 2 - small coil with a given inductance and geometry and scale up its dimensions, keeping the inductance constant, initially Q will increase nicely but simultaneously the self-resonant frequency (SRF) will decrease. At some point SRF will limit the achievable Q. Length-to
- es how much current it will oppose through the inductor
- In the case of self-inductance, the magnetic field created by a changing current in the circuit itself induces a voltage in the same circuit. Therefore, the voltage is self-induced. The term inductor is used to describe a circuit element possessing the property of inductance and a coil of wire is a very common inductor. In circuit diagrams, a.

Bring a high leakage inductance and a low leakage inductance coil with you to the track. consult the ignition companies catalog, Web site or tech line to narrow your choices of coils to test with An inductor, also called a coil, choke, or reactor, is a passive two-terminal electrical component that stores energy in a magnetic field when electric current flows through it. An inductor typically consists of an insulated wire wound into a coil.. When the current flowing through the coil changes, the time-varying magnetic field induces an electromotive force (e.m.f.) in the conductor. One way to reduce mutual inductance is to counterwind coils to cancel the magnetic field produced In an inductance, current is the time-integral of voltage.That is, the applied voltage across the inductor dictates the rate-of-change of current through the inductor over time. Challenge question: can you think of a way we could exploit the similarity of inductive voltage/current integration to simulate the behavior of a water tank's filling, or any other physical process described by the. * The coil area is measured lengthwise through the coil, at the cross-section of the core*. A larger coil area gives less opposition to the formation of a magnetic field flux given an amount of field force. It means that larger coil area results in greater inductance and a smaller coil area results in less inductance. 3. Coil lengt

* Induced emf in a coil : If there are N turns in a coil, the change in magnetic flux through the coil will induce emf in each turns*. The total emf induced in the coil will be the sum of these individual induced emfs. Here we are assuming that the coil is tightly wound (closely packed), so that the same magnetic flux passes through all the turns coffin.] InfluenceofFrequencyonSelf-Inductance. 279 TheinterpretationofTableIisasfollows:Asthefrequency increasessodoestheresistance.Takeasolidwireofanyradius. Mutual inductance can either increase or decrease the net inductance of a pair of series-connected coils, compared with the condition of zero mutual inductance. The magnetic fields around the coils either reinforce each other or oppose each other, depending on the phase relationship of the ac applied to them

Mutual inductance of the coil, Induced emf of the coil, The current through the solenoid reverse its direction if the induced emf, e = -0.2 V. Question 15. A 200 turn coil of radius 2 cm is placed co-axially within a long solenoid of 3 cm radius. If the turn density of the solenoid is 90 turns per cm, then calculate mutual inductance of the coil * The following will give a detailed answer to the question: how to check the ignition coil with a multimeter*. To do this, follow these steps: First you need to disconnect the minus on the car battery, unscrew the brackets a little, disconnect the coil wiring and clean its body. A visual inspection of the coil is also necessary at this stage The current through the coil will increase as the inductance decreases. For increased sensitivity, the coil can be separated into two coils by utilizing a center tap, as shown in Figure 7. As the core moves within the coils, the inductance of one coil will increase, while the other will decrease Coil length also affects the inductance of a solenoid. All other factors remaining unchanged, lengthening or stretching the coil reduces inductance. Shortening or compressing the coil causes an increase in inductance. The addition of a core material to a solenoid can greatly affect its inductance

5. Higher the self-inductance of a coil, (a) lesser its weber-turns (b) lower the e.m.f. induced (c) greater the flux produced by it (d) longer the delay in establishing steady current through it. 6. In an iron cored coil the iron core is removed so that the coil becomes an air cored coil. The inductance of the coil will (a) increase (b) decrease If the flux is in opposite direction to the magnetic flux, the mutual inductance will decrease; these coils are called Opposing coils. This mutual inductance will depend upon the placed distance of two coils. Consider that two inductors are connected in parallel with self inductances L 1 and L 2,. Inductance is much more significant when conductors are coiled, because the magnetic field of each turn of the coil cuts across nearby turns of the coil. To increase inductance, an inductor may have an iron core. Putting iron inside a coil greatly increases the strength of its magnetic fields. Factors Affecting Inductance of a Coil An inductor is simply a coil of wire and it has the property of self-inductance, which relates the voltage across its terminals with the change in its own magnetic field. This video will illustrate the concepts behind inductance and then demonstrate an induction experiment using a bar magnet and a coil

NEVER substitute the coil for another type on a mapped system. The ECU will not know you have done this and will still turn the coil on for a certain time, if your new coil charges quicker (lower inductance) then the coil or ECU will be damaged. If a slower charging coil is fitted (higher inductance) you will get a poor spark A coil has an inductance of 0.5H. What will be the value of the inductive reactance, if the coil has a frequency of 100Hz? Rta: // This is a theoretical example because in reality the coils have a resistive + inductive component, for our case we only have to multiply the variables of the formula in the following way: 2xπx100x0,5 = 314,16 Ohm Problem. If we wish to take into account the small inductance term / in the geophone equation (7.9a), show that, for a harmonic wave, it can be included approximately in the term involving the damping factor in equation (7.9b).. Background. The moving-coil electromagnetic geophone is widely used for land seismic work

* The mutual inductance at a frequency of 12 MHz was also determined, by substituting the above measurement results into the following formula: (8) M = V s ω I e where V s is the voltage inducted in the sensing coil when the current I e is flowing in the excitation coil*. The mutual inductance for each coil type is shown in Fig. 14. It can be. The transmitter coil has 9 turns and the receiver coil has 39 turns. I then used a digital oscilloscope to measure the voltage induced in the receiver coil at two different loading conditions - at no load and at full load. The voltage induced in the receiver coil hand an RMS voltage of 28.3 V as shown in its waveform It doesn't. the impedance of the inductor will, following the rule j*w*l, where l is inductance, w is frequency in radians and j is the imaginary number designating this a reactance, not resistance 28) This causes a dramatic increase in resistance and a decrease in inductance. 29) Mainly used as precision article of electronic industry, such as STM inductance etc. 30) The principle is independent of short-circuit reactance and leakage inductance of each side can be effectively monitored in real time Now from Lenz's law, we know that the induced current in the secondary coil would flow in such a way so as to oppose the magnetic field created by the primary coil and thus there is a slight decrease in the flux through the primary coil which would in turn increase the emf across the primary coil and thus create higher amount of electricity

** The following formula from R**. Weaver's article Numerical Methods for Inductance Calculation is used for calculations of inductance L S: where. One is the mutual inductance and another one is self-inductance. The inductance value is of two types. These units describe one thousandth and one millionth of a henry respectively 6. In an iron cored coil the iron core is removed so that the coil becomes an air cored coil. The inductance of the coil will (a) increase (b) decrease (c) remain the same (d) initially increase and then decrease. Ans: b. 7. An open coil has (a) zero resistance and inductance (b) infinite resistance and zero inductance

The inductance of a coil will increase under all the following conditions excepts. A. When more length for the same number of turns is provided. B. When the number of turns of the coil increase. C. When more area for each turn is provided. D. When permeability of the core increases. Answer/ Hin Despite this, the ferromagnetic effect does not cause the change sensed by the detector. Eddy currents induced in the vehicle decrease the inductance of the loop even more than the ferromagnetic effect raises it; therefore the net effect is a decrease in inductance. Eddy currents are explored in the following section. Eddy Current

inductance of the coil in Henry 17. If the current through an inductor of 1.2 H is reduced uniformly from 6 A to 1 A in 0.4s, then the value of the induced EMF will be DC saturation allowable current When the direct current is supplied to the inductor, inductance decreases. It represents a point that inductance begins to decrease. The decreased inductance returns to the normal value when the current becomes small decrease as the wire temperature decrea This is shown ses. graphically following and also in more detail in Application Note Coil Voltage and Temperature Compensation. Effect of Temperature on Coil Performance: Coil resistance versus temperature (Graphically): Definitions of Terminology

current coil when (a) load impedance is high (b) load impedance is low (c) supply voltage is low (d) none of the above Ans: a . 21. In a low power factor wattmeter the pressure coil is connected (a) to the supply side of the current coil (b) to the load side of the current coil (c) in any of the two meters at connectio 2 The inductance of a coil will increase under all the following conditions except 7 The law that the induced e.m.f. and current always oppose the cause producing them is due to A Faraday. B Lenz. C Newton. D None Of The Above. The inductance of coil is 6 mH. If the core length is doubled, all other quantities, remaining the same, the. (b) Write any two factors each on which the following depends : (i) Self inductance of a coil. (ii) mutual inductance of a pair of coils. (Comptt. All India 2015) Answer: (a) The self-inductance (L) of a coil equal the magnetic flux linked with it, when a unit current flows through it Two coils have mutual inductance 0. 0 0 5 H. The current changes in the first coil according to equation I = I 0 sin ω t, where I 0 = 1 0 A and ω = 1 0 0 π r a d / s. The maximum value of emf in the second coil i If the flux is in opposite direction to the magnetic flux, the mutual inductance will decrease; these coils are called Opposing coils. This mutual inductance will depend upon the placed distance of two coils