The direction of induced EMF can be found with the help of -

1 Answer

Answer :

Lenz’s Law

Related questions

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 : Which of the following will produce an induced emf: a. Changing area of coil b. Changing magnetic flux c. changing orientation of coil d. all of them

Last Answer : c. changing orientation of coil

Description : The phenomena of induced emf was observed by Faraday and Henry in: a. 1931 b. 1831 c. 1535 d. 1940

Last Answer : a. 1931

Description : In the plane of AC generator coil is parallel to the field, then emf induced in coil is: a. maximum b. minimum c. zero d. intermediate

Last Answer : b. minimum

Description : In the plane of the A.C generator coil is perpendicular to the field, then induced emf in the coil is: a. Maximum b. minimum c. zero d. intermediate value

Last Answer : b. minimum

Description : A wire loop is moved parallel to a uniform magnetic field. The induced emf in the loop: a. depends on the shape b. depends on area c. depends on nature of loop d. zero

Last Answer : d. zero

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 : The induced emf is produced in a circuit due to: a. Initial magnetic flux b. final magnetic flux c. Change of magnetic flux d. constant magnetic flux

Last Answer : d. constant magnetic flux

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 : The emission in which the atom emits a photon of energy hf = E2 – E1 , in any arbitrary direction is a) Spontaneous emission b) stimulated emission c) induced emission d) both a & c

Last Answer : d) both a & c

Description : The induced current in transformer which produced in the direction perpendicular to flux, is known as: a. Conventional current b. electronic current c. Perpendicular current d. Eddy current

Last Answer : c. Perpendicular current

Description : “The direction of induced current is always so as to oppose the change which causes the Current” is the statement of: a. Faraday’s law b. Lenz’s Law c. Ohm’s Law d. Kirchoff’s rule.

Last Answer : c. Ohm’s Law

Description : How we can find the direction of induced emf? 

Last Answer : The direction of induced emf can be find out by the Fleming's right hand rule', and lenz's law' Fleming's right hand rule : Fleming's right hand rule states that, if ... that the action of magnetic field set up by induced current tends to opposes the root cause which produces it. 

Description : What rule should you use to determine the direction of induced emf in a coil?

Last Answer : The left-hand rule for generators.

Description : The greatest induced EMF will occur in a straight wire moving at constant speed through a uniform magnetic field when the angle between the direction of the wire's motion and the direction of the magnetic field is w) 0 degrees x) 30 degrees y) 60 degrees z) 90 degrees

Last Answer : ANSWER: Z -- 90 DEGREES

Description : When a motor is just started, back emf is almost ______: a. Infinite b. zero c. minimum d. maximum

Last Answer : d. maximum

Description : If the motor is overloaded, then the magnitude of ‘back emf’” a. Increases b. Decreases c. Constant d. Becomes zero

Last Answer : Increases

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 : If velocity of a conductor moving through a magnetic field ‘B’ is made zero, then Motional emf will be: a. –VBL b. –V/BL c. – BL/V d. zero

Last Answer : a. –VBL

Description : Terminal potential difference of a battery is greater than its emf when a. the internal resistance of battery is infinite b. the internal resistance of battery is zero c. the battery is charged d. the battery is discharged

Last Answer : c. the battery is charged

Description : A neon flashlight cell with an emf of 1.5V gives a current of 15A when connected directly to an ammeter of resistance 0.04?. Internal resistance of the cell is a. 0.0004? b. 0.06? c. 0.10? d. 0.13?

Last Answer : b. 0.06?

Description : The incident photon absorbed by an atom in the ground state E1, thereby leaving the atom in the excited state E2 , is a) spontaneous absorption b) stimulated absorption c) induced absorption d) both b & c

Last Answer : d) both b & c

Description : The induced current can be increased by: a. Using strong magnetic field b. moving loop faster c. Replacing loop by coil d. all of above

Last Answer : d. all of above

Description : Fleming's left hand rule is used to find (a) direction of magnetic field due to current carrying conductor (b) direction of flux in a solenoid (c) direction of force on a current carrying conductor in a magnetic field (d) polarity of a magnetic pole

Last Answer : (c) direction of force on a current carrying conductor in a magnetic field

Description : The direction of magnetic lines of force is (a) from south pole to north pole (b) from north pole to south pole (c) from one end of the magnet to another (d) none of the above

Last Answer : (b) from north pole to south pole

Description : Electromagneticwaves are refractedwhen they a. pass into a medium of different dielectric constant b. are polarized at right angles to the direction of propagation c. encounter a perfectly conducting plane d. pass through a small slot in a conducting plane

Last Answer : a. pass into a medium of different dielectric constant

Description : How can the direction of rotation of an AC motor be reversed?*

Last Answer : By interchanging any two supply lines.

Description : Sometimes, when you change the running direction of a E/R blower (from supply to exhaust) it trips. Why?

Last Answer : If the flaps of the blower are not set or opened properly or the filters are clogged, the air supply is affected and the blower may be overloaded causing it to trip. Ask E/O for more information.

Description : How is the direction varied?

Last Answer : A general purpose DC motor can be reversed by changing the polarity of either the armature or the field but not both.

Description : How is the direction of rotation varied?

Last Answer : By changing the phase sequence (from say R-Y-B to R-B-Y)

Description : A magnetic field acts on a charged particles so as to change its: a. speed b. energy c. direction of motion d. all of these

Last Answer : Only direction of motion will change ...it means velocity will change but speed same

Description : The negative sign in expression ɛ= -vBL shows that the angle between the direction of L and (v x B) is: a. 90 b. 180 c. 45 d. 0

Last Answer : a. 90

Description : A proton beam moves towards an observer. The direction of magnetic induction is a) towards right b) anticlockwise c) towards left d) clockwise

Last Answer : d) clockwise

Description : An electron moves with a velocity of 2 × 106 ms-1 in the direction of a uniform magnetic field of 0.8 Tesla. The force on electron is a) 8 N b) 2 N c) 4 N d) Zero

Last Answer : d) Zero

Description : The current in ampere through an inductor is i(10+20t) Here t is in second. The induced emf in the inductor 4V. Total flux linked with the inductor at

Last Answer : The current in ampere through an inductor is i(10+20t) Here t is in second. The induced emf in the inductor 4V. ... 10 Wb B. 20 Wb C. 30 Wb D. 40 Wb

Description : The current in ampere through an inductor is i(10+20t) Here t is in second. The induced emf in the inductor 4V. The self inductance of the indicator i

Last Answer : The current in ampere through an inductor is i(10+20t) Here t is in second. The induced emf in the inductor 4V. The ... B. `0.4` C. `0.1` D. `1.0`

Description : Write down the equation for frequency of emf induced in an Altenator.

Last Answer : F = (PN)/120 Hz,Where P- Number of poles, N-Speed in rpm

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 : What is the equation used to find out frequency of number of cycles of induced emf?

Last Answer : f = NP/120

Description : Find the emf induced in a coil of 60 turns with a flux rate of 3 units. a) -60 b) -180 c) 60 d) 180

Last Answer : b) -180

Description : The induced emf in a material opposes the flux producing it. This is a) Faraday law b) Ampere law c) Lenz law d) Curie law

Last Answer : c) Lenz law

Description : Find the induced EMF in an inductor of 2mH and the current rate is 2000 units. a) 4 b) -4 c) 1 d) -1

Last Answer : b) -4

Description : What is meant by induced emf? By counter emf?

Last Answer : Induced emf is the emf which appears across a conductor when there is relative motion between the conductor and a magnetic field; counter emf is the emf induced in a conductor that opposes the applied voltage.

Description : Why is no emf induced in a rotating coil when it passes through the neutral plane?

Last Answer : No flux lines are cut.

Description : 28.In a two winding transformer, the emf /turn in secondary winding is always......the induced emf power turn in primary A. equal to k times B. equal to 1/k times C. equal D. greater than

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Description : 6 In a two winding transformer, the primary and secondary induced emf E1 & E2 are always A. equal in magnitude B. anti phase with each other C. in phase with each other D. determined by load on transformer secondary

Last Answer : C. In phase with each other

Description : Slip of the induction machine is 0.02 and the stator supply frequency is 50 Hz. What will be the frequency of the rotor induced emf? (A) 10 Hz. (B) 50 Hz. (C) 1 Hz. (D) 2500 Hz.

Last Answer : Ans: C Given : s = 0.02 ; f = 50 Hz Therefore, frequency of rotor induced emf = s f = 0.02 x 50 = 1.0 Hz

Description : The emf 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 : (C) leads the flux by 90 degree.

Description : Explain statically induced EMF and Dynamically induced EMF with neat diagrams.

Last Answer : Statically Induced EMF:- When changing magnetic field links with a stationary coil an emf is induced. This emf is called statically induced emf. Statically induced EMF is of two types: Self-induced ... cuts the field and an emf is induced. This emf is called dynamically induced emf.    

Description : List the types of induced emf.

Last Answer : The types of induced emf are : i) Statically induced emf , ii) Dynamically induced emf