If the permeability of the core of a coil increases, what  happens to (a) inductance and (b) true power in the circuit?

1 Answer

Answer :

(a) Inductance increases; (b) true power decreases.

Related questions

Description : If inductance increases in a series LR circuit, what happens to true power?

Last Answer : It decreases.

Description : What happens to the permeability of an iron core as the current increases from the operating point to a large value?

Last Answer : Permeability decreases

Description : Find the inductance of a coil with permeability 3.5, turns 100 and length 2m. Assume the area to be thrice the length. a) 131.94mH b) 94.131mH c) 131.94H d) 94.131H

Last Answer : a) 131.94mH

Description : A saturable-core reactor operates on the principle of controlling a load winding's inductance by varying the core's _____________. A. dielectric B. permeability C. reactance D. inductance

Last Answer : Answer: B

Description : Brush sparking during commutation may be caused by ________. A. eddy currents in the armature core B. laminations in the generator field pieces C. induced current opposite to coil inductance D. coil inductance discharge occurring at commutation

Last Answer : Answer: D

Description : What type of core produces the greatest inductance?

Last Answer : Magnetic-metal core.

Description : Three factors responsible for the change in voltage as load is applied to an AC generator are: 1) the drop in resistance in the armature circuit, 2) the change in flux, and 3) the ____________. A. armature winding speed B. inductance load drop C. coil pitch factor D. armature reactance voltage drop

Last Answer : Answer: D

Description : If two coils are wound on a single iron core, what will a change in current in one coil cause in the other coil?

Last Answer : A change in inductance.

Description : What happens to the value of XL as inductance decreases?

Last Answer : XL decreases.

Description : According to Ohm’s law, what happens to circuit current if circuit resistance (a) increases, (b) decreases?

Last Answer : (a) Current decreases (b) Current increases

Description : According to Ohm’s law, what happens to circuit current if the applied voltage (a) increases, (b) decreases?

Last Answer : (a) Current increases (b) Current decreases

Description : What happens to the H lines between the conductors of a coil when the conductors are close together?

Last Answer : The H lines cancel.

Description : What component of the D’Arsonval meter movement completes the circuit for current flow to the coil?

Last Answer : Hairspring.

Description : Which of the following statements concerning AC circuits is correct? A. The power factor of a resistive circuit is always zero. B. True power in an inductive circuit always equals apparent power. ... . D. Total opposition to the flow of alternating current depends upon the amount of reactive power.

Last Answer : Answer: C

Description : A coil =of inductance `L=50muH` and resistance =`0.5Omega` is connected to a battery of emf=5A. A resistance of `10Omega` is connected parallel to the

Last Answer : A coil =of inductance `L=50muH` and resistance =`0.5Omega` is connected to a battery of emf=5A. A resistance ... is (0.02)x in mJ. Find valuie of x.

Description : Two coils have a mutual inductance 0.005H. The current changes in the first coil according to the equation `I=I_(0) sin omegat "where" I_(0)=10A and o

Last Answer : Two coils have a mutual inductance 0.005H. The current changes in the first coil according to the equation `I ... (pi//x)` volts. Find the value of x.

Description : When number of turns in a coil is trippled, without any change in the length of coil, its self inductance becomes? (1) Nine times (2) Three times (3) Six times (4) One-third

Last Answer : (1) Nine times

Description : An open coil in a transformer will be indicated by which of the listed conditions? A. 'zero' resistance accompanied by high inductance B. no resistance accompanied by stray inductance C. infinite resistance in addition to no inductance D. infinite resistance in addition to normal inductance

Last Answer : Answer: C

Description : The inductance of a coil is measured in _____________. A. ohms B. volts C. henries D. amperes

Last Answer : Answer: C

Description : Alternating current circuits develop resistance, inductance and capacitance. The inductance of a coil is expressed in _____________. A. ohms B. mhos C. henrys D. farads

Last Answer : Answer: C

Description : A transmitted signal 5 meters in wavelength is received by an antenna coil having a 50-Ω resistance and a 0.01 H inductance. What is the capacitance of the tuner shunting the antenna coil at this point? A. 0.704 fF B. 0.704 μF C. 0.704 nF D. 0.704 mF

Last Answer : A. 0.704 fF

Description : Mention the inductance value of the peterson’s coil.

Last Answer : L=1/3wc2

Description : Find the energy of a coil of inductance 18mH and current passing through it 1.25A.(in 10 -3 order) a) 14.06 b) 61 c) 46.1 d) 28.12

Last Answer : a) 14.06

Description : The inductance is the measure of a) Electric charges stored by the material b) Emf generated by energising the coil c) Magnetic field stored by the material d) Magnetization of dipoles

Last Answer : c) Magnetic field stored by the material

Description : Due to self-inductance, the coil wires are known as: a. Insulator b. Conductor c. Inductor d. Semi-conductor

Last Answer : c. Inductor

Description : The phenomenon of producing emf in the coil due to change of current in the coil itself is called: a. mutual induction b. self-induction c. self-inductance d. mutual inductance

Last Answer : d. mutual inductance

Description : The mutual inductance of the coil depends upon: a. density of the coil b. stiffness of coil c. material of coil d. geometry of the coil

Last Answer : d. geometry of the coil

Description : When number of turns in a coil is trippled, without any change in the length of coil, its self inductance becomes? (1) Nine times (2) Three times (3) Six times (4) One–third

Last Answer : Nine times

Description : Explain the error occurred due to pressure coil inductance of electrodynamometer type wattmeter. How this error is compensated?

Last Answer : For power measurement assume that the pressure coil of wattmeter is purely restitive. Hence current taken by pressure coil Ipc is in phase with voltage across the pressure coil Vpc  ... inductive reactance XL the pressure coil circuit is made purely resistive and the error is eliminated.

Description : A coil of 500 turns is linked with a flux of 25 mwb, when carries a current of 12.5A. Calculate the value of self-inductance.

Last Answer : Ans: Self-Inductance: L = NΦ /I = 500 × 25 × 10-3 / 12.5 = 1 H

Description : An iron cored inductance coil can be modelled, over a normal operating range of networks ,as A) non-Linear bilateral element B) linear bilateral element C) linear time varying element D) non-linear time invariant element

Last Answer : An iron cored inductance coil can be modelled, over a normal operating range of networks ,as linear bilateral element

Description : A 100 turn coil has an inductance of 6 mH. If the number of turns is increased to 200, all other quantities remaining the same, the inductance will be:

Last Answer : A 100 turn coil has an inductance of 6 mH. If the number of turns is increased to 200, all other quantities remaining the same, the inductance will be: 24 mH

Description : The self inductance of a coil can be measured using (A) Wien’s Bridge (B) Schering Bridge (C) Anderson’s Bridge (D) Wheatstone Bridge

Last Answer : The self inductance of a coil can be measured using Anderson’s Bridge

Description : lt the length, number of turns and area of a coil are  doubled, the inductance of the coil

Last Answer : lt the length, number of turns and area of a coil are  doubled, the inductance of the coil is quadrupled

Description : A coil of inductance 240 mH and resistance 75 Ohm is connected in parallel with a capacitor across a 30 V, variable frequency supply. The current drawn by the circuit is found to be minimum when the supply frequency is 1 kHz. The ... (A) 40, 400 Hz (B) 10, 100 Hz (C) 20, 50 Hz (D) 50, 20 Hz

Last Answer : A coil of inductance 240 mH and resistance 75 Ohm is connected in parallel with a capacitor across a 30 V, variable frequency supply. The current drawn by the circuit is found to be minimum ... supply frequency is 1 kHz. The approximate values of Q-factor and bandwidth are, respectively 20, 50 Hz

Description : What is the value of Inductance of a coil that induces 20 V when the current through the coil changes from 12 to 20 A in 2 seconds? A. 2 H B. 3 H C. 4 H D. 5 H 

Last Answer : 5 H is the value of Inductance of a coil that induces 20 V when the current through the coil changes from 12 to 20 A in 2 seconds.

Description : The coefficient of coupling between two coils is 0.45. The first coil has an inductance of 75 mH and the second coil has an inductance of 105 mH. What is the mutual inductance between the coils?  (1) 3.54 mH (2) 7.88 mH (3) 39.9 mH (4) 189.3 mH

Last Answer : The coefficient of coupling between two coils is 0.45. The first coil has an inductance of 75 mH and the second coil has an inductance of 105 mH. 39.9 mH is the mutual inductance between the coils.

Last Answer : On doubling the number of turns of a coil the inductance Quadruples.

Description : The initial rate of rise of current through a coil of inductance 10 H when suddenly connected to a D.C. supply of 200 V is_______Vs.

Last Answer : The initial rate of rise of current through a coil of inductance 10 H when suddenly connected to a D.C. supply of 200 V is 20 Vs

Description : When both the inductance and resistance of a coil are doubled the value of?

Last Answer : When both the inductance and resistance of a coil are doubled the value of time constant remains unchanged.

Description : The inductance of a coil can be increased by?

Last Answer : The inductance of a coil can be increased by choosing core material having high relative permeability.

Description : Inductance of coil?

Last Answer : Inductance of coil increases with the increase in supply frequency.

Description : Inductance of a coil Varies?

Last Answer : Inductance of a coil Varies as directly as the cross-sectional area of magnetic core and inversely as the length of the iron path.

Description : The basic control action of a magnetic amplifier depends upon _____________. A. variations in the load capacitance B. changes in inductance C. type of core material D. construction of the core

Last Answer : Answer: B

Description : In aluminium conductors, steel core is provided to (a) compensate for skin effect (b) neutralise proximity effect (c) reduce line inductance (d) increase the tensile strength

Last Answer : (d) increase the tensile strength

Description : The inductance of a power transmission line increases with (A) decrease in line length. (B) increase in conductor diameter. (C) increase in spacing between phase conductors. (D) increase in load current carried by conductors.

Last Answer : The inductance of a power transmission line increases with  increase in spacing between phase conductors.

Description : 13) In an ideal transformer A. windings have no resistance B. core has no losses C. core has infinite permeability D. all of the above

Last Answer : D. All of the above

Description : A ferrite core has less eddy current loss than an iron core because ferrites have (A) High resistance. (B) Low resistance. (C) Low permeability. (D) High hysteresis.

Last Answer : (A) High resistance.

Description : Which of the following properties is not necessarily desirable in the material for transformer core? A. Mechanical strength B. Low hysteresis loss C. High thermal conductivity D. High permeability

Last Answer : C) high thermal conductivity

Description : Reduction in core losses and increase in permeability are obtained with transformer employing?

Last Answer : Reduction in core losses and increase in permeability are obtained with transformer employing core built-up of laminations of cold rolled grain oriented steel.