[{"id":212245,"question":"What is the range of values of power factor.","choices":[{"text":"0 to -1","value":"A"},{"text":"0 to +1","value":"B"},{"text":"0 to 2","value":"C"},{"text":"2 to 3","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":212244,"question":"The time constant of a RL circuit is.","choices":[{"text":"L/R","value":"A"},{"text":"LR","value":"B"},{"text":"R/L","value":"C"},{"text":"L2/R","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":212243,"question":"The unit of time constant RC is.","choices":[{"text":"Second","value":"A"},{"text":"second-1","value":"B"},{"text":"Second -2","value":"C"},{"text":"Second 2","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":212242,"question":"The value of mutual inductance can be increased by","choices":[{"text":"Decreasing number of turns in the coil","value":"A"},{"text":"Increasing number of turns in the coil","value":"B"},{"text":"Winding the coil on china clay","value":"C"},{"text":"Winding the coil on wooden frame","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":212241,"question":"In which of the following eddy current is not used","choices":[{"text":"Induction furnace","value":"A"},{"text":"Automobile speedometer","value":"B"},{"text":"Electromagnetic damping","value":"C"},{"text":"X- rays diffraction","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":212240,"question":"Iron loss in a dynamo arises because of.","choices":[{"text":"The resistance of armature coil","value":"A"},{"text":"The production of eddy current","value":"B"},{"text":"The presence of mechanical friction","value":"C"},{"text":"The leakage of flux","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":212239,"question":"The output of a generator which uses a split ring commutator is.","choices":[{"text":"sinusoidal A.C. wave","value":"A"},{"text":"Pulsating D.C. wave","value":"B"},{"text":"Constant D.C Voltage","value":"C"},{"text":"Linerly increasing voltage.","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":212238,"question":"In the circult, the ammeter reading is 0.5 A . If the resistance of the voltmeter is 180Ohm What is the voltmeter rediang.","choices":[{"text":"90 V","value":"A"},{"text":"100 V","value":"B"},{"text":"180 V","value":"C"},{"text":"900 V","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":212237,"question":"In an induction coil, the secondary emf is.","choices":[{"text":"Zero at the break of the circuit","value":"A"},{"text":"Zero during make of the circuit","value":"B"},{"text":"Very high during make of the circuit.","value":"C"},{"text":"Very high during break of the circuit","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":212236,"question":"A generator running in reverse may be called as.","choices":[{"text":"A.C. Generator","value":"A"},{"text":"D.C. generator","value":"B"},{"text":"Motor","value":"C"},{"text":"Commutator","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":212235,"question":"Which factor remains constant in a transformer.","choices":[{"text":"Current","value":"A"},{"text":"Voltage","value":"B"},{"text":"Power","value":"C"},{"text":"Frequency","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":212234,"question":"If the transformer turns ratio is 2 and the impedance of primary coil is 250 Ohms then the impedance secondary coil will be.","choices":[{"text":"125 Ohms","value":"A"},{"text":"250 Ohms","value":"B"},{"text":"500 Ohms","value":"C"},{"text":"1000 Ohms","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":212233,"question":"If the transformer turns ratio is 2 and the impedance eof primary coil is 250 Ohms then the impedance secondary coil will be.","choices":[{"text":"125 Ohms","value":"A"},{"text":"250 Ohms","value":"B"},{"text":"500 Ohms","value":"C"},{"text":"1000 Ohms","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":212232,"question":"The long distance transmission of electrical energy is done at.","choices":[{"text":"High potential and low current","value":"A"},{"text":"High potential and highs current","value":"B"},{"text":"Low potential and high current","value":"C"},{"text":"Low potential and low current","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":212231,"question":"Why does a transformer have a core made of iron.","choices":[{"text":"Iron has a high melting point","value":"A"},{"text":"Iron is a magnetic material","value":"B"},{"text":"Iron potential and high current","value":"C"},{"text":"Iron is a conductor of electricity","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":212230,"question":"A step up transformer has a turn ratio of 1:100 A voltage of 20 V is connected across the primary coil What is the secondary voltage.","choices":[{"text":"0.2 V","value":"A"},{"text":"5 V","value":"B"},{"text":"100 V","value":"C"},{"text":"2000 V","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":212229,"question":"A transformer is needed to convert a mains 240 V supply into a 12 V supply it there are 200 turns on the primary coil, how many turns should there be on the secondary coil.","choices":[{"text":"100","value":"A"},{"text":"200","value":"B"},{"text":"400","value":"C"},{"text":"600","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":212228,"question":"The cause of production of eddy current is the","choices":[{"text":"Current flowing in a conductor","value":"A"},{"text":"Current flowing in a insulator","value":"B"},{"text":"Motion of a conductor in a varying magnetic field","value":"C"},{"text":"Motion of an insulator in a varying magnetic field","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":212227,"question":"Eddy current can be minimized by","choices":[{"text":"Moving the conductor rapidly","value":"A"},{"text":"Moving the conductor slowly","value":"B"},{"text":"Using a metallic core","value":"C"},{"text":"Using a laminated core","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":212226,"question":"A straight copper wire a moved in a uniform magnetic field such that it cuts the magnetic lines of force then.","choices":[{"text":"emf will not be induced","value":"A"},{"text":"emf will beinduced","value":"B"},{"text":"sometimes emf will be induced and sometimes not","value":"C"},{"text":"The number of turns iin the coil increases","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":212225,"question":"A transformer is used to.","choices":[{"text":"Convert D.C. into A.C.","value":"A"},{"text":"Convert A.C. in to D.C.","value":"B"},{"text":"Obtain A.C. voltage","value":"C"},{"text":"Enhance the power","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":212224,"question":"A device which converts electrical energy into mechanical energy is called.","choices":[{"text":"A.C generator","value":"A"},{"text":"D.C. generator","value":"B"},{"text":"Motor","value":"C"},{"text":"Commutator","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":212223,"question":"In what form is the energy stored in an inductor.","choices":[{"text":"Magnetic","value":"A"},{"text":"electrostatic","value":"B"},{"text":"Magnetic and electrostatic","value":"C"},{"text":"All of the above","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":212222,"question":"Under which of the following conditions current in a circuit is wattles.","choices":[{"text":"When inductance in the circuit is zero","value":"A"},{"text":"When resistance in the circuit is zero","value":"B"},{"text":"When current is alternating","value":"C"},{"text":"When resistance and inductance both are zero","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":212221,"question":"The device in the circuit that consume electrical energy are known as.","choices":[{"text":"Resistors","value":"A"},{"text":"Capacitors","value":"B"},{"text":"Fuses","value":"C"},{"text":"Load","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":212220,"question":"The core of a transfer is made of iron because","choices":[{"text":"Iron is a good electric material","value":"A"},{"text":"Iron is cheaper than copper","value":"B"},{"text":"Iron is easily magnetized and demagnetized","value":"C"},{"text":"Iron makes a good permanent magnet","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":212219,"question":"Direct current generators use.","choices":[{"text":"Coiled rings","value":"A"},{"text":"Split rings","value":"B"},{"text":"slip rings","value":"C"},{"text":"solenoid rings","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":212218,"question":"When a wire moves perpendicularly to a magnetic field, the induced emf does ot depends upon","choices":[{"text":"The velocity of the wire","value":"A"},{"text":"The resistance of the wire","value":"B"},{"text":"The flux density of the magnetic","value":"C"},{"text":"The orientation of the wire field","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":212217,"question":"The direction of induced emf during electromagnetic induction can be determined by making use of.","choices":[{"text":"Faraday's law","value":"A"},{"text":"Ampere;s law","value":"B"},{"text":"Lenz's law","value":"C"},{"text":"Laplace law","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":212216,"question":"On which principle the induction coil works on.","choices":[{"text":"Self induction","value":"A"},{"text":"Ampere's rule","value":"B"},{"text":"Mutual induction","value":"C"},{"text":"Gauss's law","value":"D"},{"value":"E"}],"correctAnswer":3}]