1 Answer

Answer :

When a magnet is in motion relative to a coil the induced e.m.f. does not depend upon resistance of the coil.

Related questions

Description : Can a static magnet induce an e.m.f in a stationary coil of wire? Give reasons.

Last Answer : No, when both coil and magnet are stationary, the magnetic field linked with the coil remains constant. Only when the magnetic field linked with the coil changes, current is produced.

Description : Give reason: Stationary coil and stationary magnet cannot produce induced electric current.

Last Answer : An emf is induced in the coil only when there is relative motion between the coil and the magnet.

Description : Induced current in coil by a magnet turns it into an A. straight wire B. magnet C. ammeter D. electromagnet

Last Answer : electromagnet

Description : How can electric currents be induced with a coil and a magnet?

Last Answer : by moving either the magnet or the coil

Description : The introduction of interpoles in between the main pole improves the performance of d.c. machines, because (A) The interpole produces additional flux to augment the developed torque. (B) The flux waveform is ... armature is removed. (D) A counter e.m.f. is induced in the coil undergoing commutation.

Last Answer : Ans: D Counter e.m.f is produced, it neutralizes the reactive emf.

Description : On what factors does the induced emf in the coil depend?

Last Answer : Induced e.m.f in a coil increases with increase in: a) the number of turns of the coil, b) the strength of the magnetic field c) the speed with which the magnet or the coil moves d) area of the coil

Description : A rectangular magnet of magnetic moment M is cut into two piece of same length, the magnetic moment of each piece will be

Last Answer : A rectangular magnet of magnetic moment M is cut into two piece of same length, the magnetic moment of each piece will be M/2.

Description : E.M.F for a coil depends upon A. the cross sectional area B. no. of turns of wire C. the magnitude of magnetic flux density D. all of above

Last Answer : all of above

Description : The induced emf in a coil depends upon: a. Strength of magnetic field b. Resistance of the coil c. area of the coil d. All of them

Last Answer : d. All of them

Description : The current flowing in a coil due to induced emf depends upon: a. shape of coil b. resistance of coil c. area of coil d. magnetic flux

Last Answer : a. shape of coil

Description : What transmission method does NOT depend on relative frequency or target motion?

Last Answer : Pulse modulation.

Last Answer : Magnetism of a magnet can be destroyed by heating, hammering, by inductive action of another magnet.

Last Answer : The bar magnet has the dipole moment.

Last Answer : A permanent magnet attracts some substances and repels others.

Last Answer : The most effective and quickest may of making a magnet from soft iron is by placing it inside a coil carrying current.

Description : The working of a meter is based on the use of a permanent magnet. In order to protect the meter functioning from stray magnetic fields

Last Answer : The working of a meter is based on the use of a permanent magnet. In order to protect the meter functioning from stray magnetic fields a soft iron shielding is used.

Description : Mention the factors on which the magnitude of the e.m.f induced in the transformer depends.

Last Answer : 1) E.m.f in the primary coil 2) Number of turns in the primary coil 3) Number of turns in the secondary coil 4) The core material

Description : Magnitude of induced e.m.f is proportional to A. rate of change of current B. rate of change of voltage C. rate of change of magnetic flux linkage D. rate of change of resistance

Last Answer : rate of change of magnetic flux linkage

Description : A straight wire of length 0.20 m moves at a steady speed of 3.0 m s-1 at right angles to the magnetic field of flux density 0.10 T. The e.m.f induced across ends of wire is A. 0.5 V B. 0.06 V C. 0.05 V D. 0.04 V

Last Answer : 0.06 V

Description : E.M.F can be induced in a circuit by A. changing magnetic flux density B. changing area of circuit C. changing the angle D. all of above

Last Answer : all of above

Description : The left hand rule correlates to (a) current, induced e.m.f. and direction of force on a conductor (b) magnetic field, electric field and direction of force on a conductor (c) self induction, ... and direction of force on a conductor (d) current, magnetic field and direction of force on a conductor

Last Answer : (d) current, magnetic field and direction of force on a conductor

Description : Which of the following quantity maintains the same direction whether a D.C. machine runs as a generator or as a motor a. Induced e.m.f. b. Armature Current c. Field Current d. Supply Current  

Last Answer : Which of the following quantity maintains the same direction whether a D.C. machine runs as a generator or as a motor a. Induced e.m.f. b. Armature Current c. Field Current d. Supply Current  

Description : Which law states that induced e.m.f and current always opposes the cause producing them?

Last Answer : Lenz's law states that induced e.m.f and current always opposes the cause producing them.

Description : These self inductance of a circuit is defined as twice the work done against the induced e.m.f. on establishing unit current in the coil. If the current to be established in the coil is doubled, the work done ... induced e.m.f. will be  1. Doubled  2. Halved  3. four times  4. Quarter times 

Last Answer : These self inductance of a circuit is defined as twice the work done against the induced e.m.f. on establishing unit current in the coil. If the current to be established in the coil is doubled, the work done against the induced e.m.f. will be four times

Description : The e.m.f. induced in the primary of a transformer:  (A) is in phase with the flux (B) lags behind the flux by 90 degree (C) leads the flux by 90 degree (D) is in phase opposition to that of flux

Last Answer : The e.m.f. induced in the primary of a transformer: leads the flux by 90 degree 

Description : The voltage regulation of an alternator having 0.75 leading p.f. load, no-load induced e.m.f. of 2400V and rated terminal voltage of 3000V is —————————————  A) 20% B) —20% C) 150 D) -26.7

Last Answer : -20

Last Answer : For the production of induced e.m.f. field system of an electric machine may be on stator or rotor.

Description : The induced e.m.f. in the armature conductors of a d.c. motor is?

Last Answer : The induced e.m.f. in the armature conductors of a d.c. motor is sinusoidal.

Description : If residual magnetism is present in a D.C. generator, the induced e.m.f. at zero speed will be?

Last Answer : If residual magnetism is present in a D.C. generator, the induced e.m.f. at zero speed will be zero.

Last Answer : In any rotating machine that part which houses the conductors and in which e.m.f. induced is to be utilised is called armature.

Description : The e.m.f. induced in the armature of a shunt generator is 600 V. The armature resistance is 0.1 ohm. If the armature current is 200 A, the terminal voltage will be?

Last Answer : The e.m.f. induced in the armature of a shunt generator is 600 V. The armature resistance is 0.1 ohm. If the armature current is 200 A, the terminal voltage will be 580 V.

Last Answer : If B is the flux density, I the length of conductor and v the velocity of conductor, then induced e.m.f. is given by Blv.

Last Answer : While applying Fleming's right-hand rule to And the direction of induced e.m.f., the thumb points towards direction of motion of conductor, if forefinger points along the lines of flux.

Last Answer : Fleming's right-hand rule regarding direction of induced e.m.f., correlates magnetic flux, direction of motion and the direction of e.m.f. induced.

Description : According to Fleming's right-hand rule for finding the direction of induced e.m.f., when middle finger points in the direction of induced e.m.f., forefinger will point in the direction of?

Last Answer : According to Fleming's right-hand rule for finding the direction of induced e.m.f., when middle finger points in the direction of induced e.m.f., forefinger will point in the direction of lines of force.

Last Answer : When the armature of a D.C. motor rotates, e.m.f. induced is back e.m.f.

Description : The pole pieces of the magnet used in a pivoted coil galvanometer are

Last Answer : The pole pieces of the magnet used in a pivoted coil galvanometer are A. plane surfaces of a ... magnet D. cylindrical sufaces of a horse-shoe magnet

Description : Which of the following electric meter movements uses a stationary permanent magnet and movable coil? A. D'Arsonval B. Electrodynamometer C. Moving iron-vane D. Inclined coil iron-vane

Last Answer : Answer: A

Description : By accelerating the magnet inside the coil, the current in it A. increases B. decreases C. remains constant D. reverses

Last Answer : increases

Description : Permanent-magnet moving coil instrument can be used in

Last Answer : dc work only

Description : What is the reason why the scale of a permanent-magnet moving coil instrument is uniform?

Last Answer : because it is spring controlled

Description : Magnetic flux linked with a coil can be changed by using an: a. Permanent magnet b.Bar magnet c. Electromagnet d. Horseshoe magnet

Last Answer : b.Bar magne

Description : Which component is mainly used in a DC generator: a.slip ring b. commutator c. magnet d. coil

Last Answer : b. commutator

Description : The pole faces of U-shaped magnet in a moving coil galvanometer are made concave to a) decrease the strength of magnetic field b) create a non-uniform magnetic field c) make the magnetic field radial d) All of these

Last Answer : c) make the magnetic field radial

Description : Permanent Magnet Moving Coil (PMMC) Instrument

Last Answer : Permanent Magnet Moving Coil (PMMC) Instrument

Description : A permanent magnet moving coil instrument gives full scale deflection of 25mA when a voltage of 75mV is applied across it. Calculate: (i) Resistance of shunt required for full scale deflection of 150 A. (ii) Series resistance for full scale deflection of 500 V.

Last Answer : Answer :

Description : Name the material used for :- (i) Moving coil (ii) Permanent magnet in PMMC instrument.

Last Answer : (i) Material used for Moving coil: Copper, Aluminum( some times)  (ii) Permanent magnets are made of special alloys such as :  Aluminum-Nickel-Cobalt (Alnicos)  Strontium-Iron  Neodymium-Iron-Boron  Samarium-Cobalt.

Description : A permanent magnet moving coil ammeter has a coil resistance of 99 ohm and Full Scale Deflection (FSD) current of 0.1mA. Shunt resistance is 1 ohm. Current through the meter at 0.5 F.S.D is:

Last Answer : A permanent magnet moving coil ammeter has a coil resistance of 99 ohm and Full Scale Deflection (FSD) current of 0.1mA. Shunt resistance is 1 ohm. Current through the meter at 0.5 F.S.D is: 0.05mA

Description : Permanent magnet moving coil instruments are used for

Last Answer : PMME are mostly used for measuring voltage and current.

Description :  The main sources of Errors in Permanent Magnet moving Coil (PMMC) are due to : - a) weaking of the permanent magnet due to aging at temperature effects b) weaking of spring due to aging and temperature effects c) change of resistance of the moving coil with temperature d) all the above

Last Answer :  The main sources of Errors in Permanent Magnet moving Coil (PMMC) are due to : - a) weaking of the permanent magnet due to aging at temperature effects b) weaking of spring due to aging and temperature effects c) change of resistance of the moving coil with temperature d) all the above