BEE Unit 1 Basic Electrical Fundamentals GGSP.pdf

GURU GOBIND SINGH POLYTECHNIC, NASHIK FYCO A BEE MCQ (Electrical) UNIT 01:-Basic Electrical Fundamentals Sr.No. 1 2 3 4 5 Question The right hand rule for determining the direction of the induced EMF was introduced by Whenever the magnetic flux changes with respect to an electric conductor or a coil...

GURU GOBIND SINGH POLYTECHNIC, NASHIK FYCO A BEE MCQ (Electrical) UNIT 01:-Basic Electrical Fundamentals Sr.No. 1 2 3 4 5 Question The right hand rule for determining the direction of the induced EMF was introduced by Whenever the magnetic flux changes with respect to an electric conductor or a coil, an EMF is induced in the conductor is Faraday’s Which of the following represents ohms law Conductor is static and the field is varying then emf will be induced. This principle is called A conductor of length L has current I passing through it, when it is placed parallel to strong magnetic field. The force experienced by the conductor will be In the left hand rule, forefinger always represents Cork Screw rule is used to find 10 11 12 C D Ans Faraday Lenz Fleming Maxwell Fleming first law second law third law fourth law first law V = RI J = σE I = GV All of the above All of the above none of these static induced emf. virtually induced emf. BIL. dynamical static induced ly induced emf. emf. BL2I. BI2L zero zero current. magnetic field. direction of force on the conductor. magnetic field. direction of emf direction of current zero parallel to axis. none of above. (A) and (B) both in the same way. weber / meter2. 1 wb/m. none of them. weber / meter2. 1 wb/ m2. magnetic flux. direction of direction of magnetic electric field. field. at angle of perpendic parallel to 45° with ular to the axis. the axis axis. direction of current 7 9 B voltage. 6 8 A The field at any point on the axis of a current carrying coil will be The change of cross sectional area of reluctance resistance (A) and (B) conductor in magnetic field will of of both in the affect conductor. conductor. same way. Unit of magnetic flux density is 1 Tesla = The tubes of force within the magnetic material are known as farad / meter. 1 wb- m2. 1 wb/ m2. lines of tubes of force. indication. coulomb. coulomb / meter2. 1 wb. magnetic flux. How does the magnetic compass needle behave in a magnetic field? 13 14 15 16 17 18 19 20 21 22 23 24 25 26 It assures a It assures a position position right angle It starts which None of to rotating. follows a line above. magnetic of magnetic field. flux. A magnetic material has a total flux B of 80 micro Wb with an mmf of 2 × 10-6 2 × 10+6 2 × 10-8 160 AT. The reluctance in ampere turn per weber is Which of following is not a unit of Maxwell. Telsa. Weber. flux? Which of following circuit element Condenser Variable stores energy in electro-magnetic Inductor.. Resistor. field? An emf of 16 volts is induced in a coil of inductance 4 H. The rate of 64 A / s. 32 A / s. 16 A / s. change of current must be Which of following can induce the 1 amp 1 1 amp 100 1 amp dc. maximum induced voltage ? Hz. Hz. The emf induced in a conductor DC and AC DC. AC. rotating in bipolar field is both. flux The magnitude of the induced emf density of in a conductor depends upon on the amount of amount of the flux cut. flux linkage. magnetic field. The property of the coil by which a mutual counter emf is induced in it when self series aiding inductanc the current through the coil changes inductance. inductance. e. is known as A coil is wound on iron core which carries current I. The self-induced variation in Variation change the voltage in the coil is not affected by coil in voltage number of current. in the coil. turns of coil. A conductor of length 100 cm moves at right angles to a magnetic field of flux density 1.5 Wb/m2 with a velocity of 50 m/s. The induced emf in the conductor will be 150 V. 50 V. 75 V It assures a position which follows a line of magnetic flux. 2 × 10+8 2 × 10+6 All of above. Telsa. Capacitor. Inductor. 4 A / s. 4 A / s. S= mmf/Flu x 20 amp 1 amp 100 dc. Hz. none of AC. these. rate of rate of change of change of flux flux linkage. linkage. capacitanc self e. inductance. the resistance Variation in of voltage in magnetic the coil. path. 50.5V. 75 V When a magnet is in motion relative pole motion of number of to a coil the induced emf does not strength of resistance of resistance of the turns of depend upon the the coil. the coil. magnet. the coil. magnet. The direction of induced emf can be Kirchhoff Flemings Laplaces found by s voltage Lenzs law. right hand Lenzs law. law. law. rule. Which of following is the unit of Ampere MilliMilliOhm. Webers / m. inductance? turns. henry. henry. induced EMF (E) = B × L× V = 100 × 10-2 × 1.5 × 50 = 75 Volts For DC voltage an inductor is virtually a 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 In AC magnitude and direction Remain… In DC magnitude and direction Remain… frequency in DC… frequency in india Inductor does not allow the sudden change of Capacitor does not allow the sudden change of Which quantity should be measured by the voltmeter Which quantity consists of a unit 1KWh Which of the following quantities consists of SI unit as WATT Rms value is defined based on which of the following Which of the following defined the average value ? The alternative names for active power is/are Under resonance condition the phase angle between voltage phase and current phase is The maximum value of a current wave is 2A. If the form factor of a current wave is 1.5 and the peak factor is 2.7, find the rms value in Amperes. The maximum value of a current wave is 2A. If the form factor of a current wave is 1.5 and the peak factor is 2.7, find the average value in Amperes. A balanced star connected load with impedance of 30j - 300 Ω is supplied from a 3 - phase, 4-wire, 173 V system, the voltages to neutral being 100j -900, 100j - 300 and 100j -1500 V. The current in neutral wire is Form Factor For sinusoidal waveform is.. Peak Factor For sinusoidal waveform is.. depends depends on on polarity. magnitude of voltage. short circuit. open circuit. constant same constant same 0Hz 0Hz 50Hz 50Hz 25Hz 25Hz current voltage power current voltage power current voltage power Speed voltage Energy Time Power Charge Energy Force Charge Current Power Power Heating effect Heating effect Charge transfer Charge transfer average power. current voltage current voltage true power. all of the above. Heating effect Charge transfer all of the above. real power. short circuit. change with none of change with time the above time change with none of constant time the above 70Hz 70Hz None of the above None of the above 0Hz 50Hz current voltage 0° 90° 80° 70° 0° 0.494 A. 0.741 A 1.57 A. 1.414 A. 0.741 A 1.414 A. 0.494 A. 0.741 A 1.57 A. 0.741 A zero. 1.414 A. 0.494 A. 0.741 A zero. 1.11 1.41 1.2 1.225 1.11 1.11 1.41 1.2 1.225 1.41 49 The N Point in Star Connection is know as.. Phase Sequence is… Mechanical degree in 3 Conductore is…. In Star Connection Line Voltage and Phase voltage are 50 In Sdelta Connection Line Voltage and Phase voltage are same 51 In Star Connection Line Current and Phase Current are same 52 In Delta Connection Line Current and Phase Current are same 46 47 48 53 54 55 56 57 option A option A & &B B BRY RYB Neutral star comman RYB YRB RBY 60 120 180 240 120 double VL/2 √3 times the phase voltage double VL/2 same double IL/2 same double IL/2 √3 times the phase current same √3 times the phase voltage √3 times the phase voltage √3 times the phase current √3 times the phase current In Delta connection Nuetral Point both A & Present Absent Obtaiend is…. C Condition for a balanced 3 - phase all of load is that, each phase has the same impedance. resistance. power factor. these. value of Phase voltages of a star connected alternator are ER = 240∠0o V, EY = 240∠-120o V and EB = 240∠ + RYB YRB RBY BRY 120o V. What is the phase sequence of the system? 3 phase balanced load means all of Z1=Z2=Z3 I1=I2=I3 P1=P2=P3 these. 3 phase Unbalanced load means all of Z1≠Z2≠Z3 I1≠I2≠I3 P1≠P2≠P3 these. both A & C all of these. RYB all of these. all of these. Prepared by, D.P.Kumbharde