The induced voltage across a coil with 250 turns that is located in a magnetic field and is changing at a rate of 8 Wb/s is 2,000 V
Description : A coil of wire is placed in a changing magnetic field. If the number of turns in the coil is decreased, the voltage induced across the coil will: A. increase B. decrease C. remain constant D. be excessive
Last Answer : A coil of wire is placed in a changing magnetic field. If the number of turns in the coil is decreased, the voltage induced across the coil will: decrease
Description : The voltage induced across a certain coil is 200 mV. A 1200 resistor is connected to the coil terminals. The induced current will be: A. 1.7 mA B. 16 mA C. 12 mA D. 120 mA
Last Answer : The voltage induced across a certain coil is 200 mV. A 1200 resistor is connected to the coil terminals. The induced current will be: 1.7 mA
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 : If coil 'R1-R2' on the transmitter in figure 'A' shown in the illustration is turned 30 degrees clockwise, corresponding coil 'R1-R2' on the receiver should ____________. EL-0092 A. make coils 'S1 ... a higher voltage depending on the turns ratio D. align itself to the same position if free to move
Last Answer : Answer: D
Description : The amount of voltage induced in the windings of an AC generator depends on ____________. A. the number of conductors in series per winding B. the speed at which the magnetic field passes across the winding C. the strength of the magnetic field D. all of the above
Description : One method of testing for a reversed shunt field coil in a DC generator or motor is by connecting the field to a direct current source, at reduced field rated voltage, and test for ... placed near each field C. test lamp across adjacent fields D. copper jumper across the interpole connections
Last Answer : Answer: B
Description : A short in the shunt field of a DC motor is best located by _____________. A. visual inspection of the commutator B. applying AC voltage to each field coil and measuring the voltage drop across ... using a growler and hacksaw blade D. isolating each coil from the others and using a megohmmeter
Description : The frequency of an alternator at a given RPM is determined by the _____________. A. number of turns of wire in the armature coil B. number of magnetic poles C. strength of the magnets used D. output voltage
Description : One factor that determines the frequency of an alternator is the ____________. A. number of turns of wire in the armature coil B. number of magnetic poles C. strength of the magnets used D. output voltage
Description : A rectangular coil of copper wires is rotated in a magnetic field. The direction of the induced current changes once in each -Physics-10
Last Answer : half revolution When a rectangular coil is rotated in magnetic field, the direction of the induced current changes once in half revolution. As a result, the direction of the current in the coil remains the same. In text 13.7 Page:238
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 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 : Find the magnetic field intensity due to a solenoid of length 12cm having 30 turns and current of 1.5A. a) 250 b) 325 c) 175 d) 375
Last Answer : d) 375
Description : A planar coil having 12 turns carries 15 A current. The coil is oriented with respect to the uniform magnetic field `B= 0.2hati T` such that its direc
Last Answer : A planar coil having 12 turns carries 15 A current. The coil is oriented with respect to the ... energy of the coil in the given orientation is
Description : A square coil of edge I having n turns carries a curent i. it is kept on a smooth horizontal plate. A uniform magnetic field B exists in a direction p
Last Answer : A square coil of edge I having n turns carries a curent i. it is kept on a smooth horizontal plate. A uniform ... . `(Mg)/(4niL)` D. `(2Mg)/(niL)`
Description : A 100 turns coil shown in figure carries a current of 2 amp in a magnetic field `B=0.2 Wb//m^(2)`. The torque acting on the coil is
Last Answer : A 100 turns coil shown in figure carries a current of 2 amp in a magnetic field `B=0.2 Wb//m^( ... N-m` tending to rotate the side AD into of the page
Description : A current of `0.1 A` circulates around a coil of 100 turns and having a radius equal to `5 cm`. The magnetic field set up at the centre of the coil is
Last Answer : A current of `0.1 A` circulates around a coil of 100 turns and having a radius equal to `5 cm`. The magnetic ... C. `4pixx10^(-5)T` D. `2pixx10^(-5)T`
Description : Sensitivity of a galvanometer can be increased by a) Increasing the number of turns of the coil b) Decreasing the magnetic field c) Increasing the ratio c ⁄BAN d) Decreasing the area of the coil
Last Answer : a) Increasing the number of turns of the coil
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 : 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 : 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 : When troubleshooting a motor controller, all indications are that a relay coil should be energized. If there were no magnetic pull, with rated voltage measured across the coil, the most probable cause ... open C. auxiliary contact in series with the coil is defective D. relay armature is stuck
Last Answer : Answer: A
Description : The amount of voltage induced in the windings of an AC generator depends mainly on _____________. A. the number of field poles energized B. the speed at which the stator windings rotate through the magnetic field C. the strength of the magnetic field D. all of the above
Last Answer : Answer: C
Description : In a three-phase, squirrel-cage type, induction motor the rotating magnetic field is established by the _____________. A. current induced in the rotor windings B. application of a three-phase voltage ... caused by the induced current in the squirrel-cage bars with the magnetic field of the stator
Description : : Moving a coil in and out of magnetic field induces A. force B. potential difference C. e.m.f D. voltage
Last Answer : e.m.f
Description : What is the mathematical formula for computing the output voltage from a moving coil in a magnetic field?
Last Answer : 8. e = Emax sine θ.
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 : Self induced voltage across an inductance
Last Answer : Self induced voltage across an inductance
Description : A circular coil of radius `10 cm "and" 100` turns carries a current 1A. What is the magnetic moment of the coil?
Last Answer : A circular coil of radius `10 cm "and" 100` turns carries a current 1A. What is the magnetic moment of the coil? A. ... 3,142 A-m^(2)` D. `3 A-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 : 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
Description : When is the maximum voltage induced into a stator coil?
Last Answer : When the rotor coil is aligned with the stator coil.
Description : The voltage across a coil, when di/dt = 20 mA/s and L = 8 H, is: A. 16 mV B. 160 mV C. 1.6 mV D. 2.5 mV
Last Answer : The voltage across a coil, when di/dt = 20 mA/s and L = 8 H, is: 160 mV
Description : 52 A transformer has 1000 primary turns, connected to 250V ac supply. To get 400V secondary voltage the no of secondary turns should be A. 1600 B. 250 C. 400 D. 1250
Last Answer : A. 1600
Description : The frequency output of an operating alternator is controlled by the _____________. A. relative speed of the rotor poles B. number of turns of wire in the armature coil C. strength of the magnets used D. output voltage
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
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
Description : An open shunt field in a direct current machine may be located by connecting the field circuit to an external power source, equal to the rated field voltage or less, and tested with a voltmeter from ... C. any suitable ground to any available line lead D. any field pole to each field coil lead
Description : An iron ring of mean circumference 80 cm is uniformly wound with 500 turns of wire and carries 0.8A. Find the magnetic field strength.
Last Answer : Ans: Magnetic field strength H = NI /l = 500 x 0.8 / 80 x 10-2 = 500 AT/m
Description : The magnetic field on the axis of a current carrying polygonal coil will have only a horizontal component parallel to the Plane of the coil
Last Answer : The magnetic field on the axis of a current carrying polygonal coil will have only a horizontal component parallel to the Plane of the coil it is never possible
Description : If two AC generators have just been placed in parallel, the true power load is initially distributed evenly by _____________. A. a balance coil B. changing field excitation C. adjusting the governor control settings D. a rheostat
Description : In the illustrated circuit, if the input to leads 'B' and 'Y' was 24 VDC the output between 'A' and 'X' will be _________. EL-0069 A. 24 VDC B. 22.8 VDC, 24 VDC minus the 1.2 VDC voltage drop across two diodes C. undeterminable without knowing the turns ratio of the transformer D. 0 VDC
Description : Figure 'D' of the diagram shown in the illustration has a turns ratio of four to one. If a three-phase 440 volt supply is connected to terminals 'A-B-C', what voltage should develop across terminals 'a-b-c'? EL-0084 A. 64 volts B. 110 volts C. 190 volts D. 762 volts
Description : Figure 'C' of the diagram shown in the illustration has a turns ratio of four to one. If a three-phase 440 volt supply is connected to terminals 'A-B-C', what voltage should develop across terminals 'a-b-c'? EL-0084 A. 64 volts B. 110 volts C. 190 volts D. 762 volts
Description : Figure 'B' of the diagram shown in the illustration has a turns ratio of four to one. If a three-phase 440 volt supply is connected to terminals 'A-B-C', what voltage should develop across terminals 'a-b-c'? EL-0084 A. 64 volts B. 110 volts C. 190 volts D. 762 volts
Description : Figure 'A' of the diagram shown in the illustration has a turns ratio of four to one. If a three-phase 440 volt supply is connected to terminals 'A-B-C', what voltage should develop across terminals 'a-b-c'? EL-0084 A. 64 volts B. 110 volts C. 190 volts D. 762 volts
Description : A load with an impedance of 440 ohms is connected across the secondary of the transformer illustrated. If the input voltage is 110 VAC and the step-up ratio is 10 to 1, what will be the primary current? EL-0055 A. 2.5 amps B. 25 amps C. 250 amps D. current cannot be determined with information given
Description : A load with an impedance of 440 ohms is connected across the secondary of the device illustrated. If the input voltage is 110 VAC and the step-up ratio is 10 to 1, what will be the primary current? EL-0055 A. 2.5 amps B. 25 amps C. 250 amps D. current cannot be determined with information given
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