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1) A small coil lies inside a large coil. The two coils are horizontal concentric and carry currents in opposite directions. The large coil will experience a. A torque about horizontal axis b. A torque about vertical axis c. An upward force along the axis d. No resultant force
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2) An aeroplane of wingspan 10m flies from the equator towards the North Pole. The wings are perpendicular to the vertical component of the earths magnetic field (B = 4x10-5T). At maximum speed an emf of 96mV is induced across the wing tips. The maximum speed of the aeroplane is a. 150msec-1 b. 384msec-1 c. 38.4msec-1 d. 200msec-1
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3) A.C can not be used for a. producing heat b. producing light c. Magnetizing iron d. Producing magnetic field
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4) Non inductive resistances are used in decreasing a. Mutual inductance b. Self inductance c. Magnetic fields d. Heating effect
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5) Magnetic compass needle will be deflecting if it is kept near a. Static charge b. Soft iron c. Semi-conductor d. Accelerating charge
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6) Long distance transmission is easy for a. D.C voltage b. A.C voltage c. Half A.C voltage d. Half D.C voltage
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7) Which one of the following devices does not function like an electric motor? a. Galvanometer b. Ammeter c. Voltmeter d. Transformer
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8) The out put voltage of a transformer is 3 times the input voltage then turns ratio will be a. 3-Jan b. 3 c. 1 d. 6
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9) For long distance transmission the transformer used is a. Step down b. Input voltage and output voltage remain same c. Step up d. Amplifier is used
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10) An electric current induced within the body of a conductor when that conductor either moves through a non uniform magnetic field or in a region where there is a change in magnetic flux is called a. Induced current b. Eddy current c. Back emf d. None of the above
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11) Lagging of changes in the magnetization of a substance behind changes in the magnetic field as the magnetic field is varied is known as magnetic a. Retaintivity b. Permeability c. Flux d. Hysteresis
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12) Transformer works on the principle of a. Lenzs law b. Faradays law c. Mutual induction d. Law of conservation of power
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13) When the motor is at its maximum speed then back emf will be a. Maximum b. Zero c. Intermediate values d. No back emf
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14) Electrons present in p-type material due to thermal pair generation are a. majority carriers b. minority carriers c. dual carriers d. blockers
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15) Semi-conductors with donor atoms and free electrons belong to the type a. n b. p c. mix d. any of above
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16) Semi-conductor germanium and silicon are a. pentavalent b. trivalent c. divalent d. tetravalent
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17) Acceptor and donor impurities donate a. n-carriers only b. p-carriers only c. p-carriers and n-carriers respectively d. n-carriers and p-carriers respectively
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18) p-n junction when reversed biased acts as a a. capacitor b. inductor c. on switch d. off switch
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19) In p-n-p transistor the collector current is a. equal to emitter current b. slightly less than emitter current c. greater than emitter current d. any of above
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20) In n-p-n transistor, p works as a. collector b. emitter c. base d. any of above
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21) The simplest type of rectification known as half wave rectification is obtained by a. using a transistor b. suppressing the harmonics in A.C voltage c. suppressing half wave of A.C supply by using diode d. using a Coolidge tube
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22) Identify the correct statement about minority carriers a. holes in n-type and free electrons in p-type b. holes in n-type and p-type c. free electrons in n-type and holes in p-type d. free electrons in n-type and p-type
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23) Depletion region of a junction is formed a. during the manufacturing process b. under forward bias c. under reverse bias d. when temperature varies
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24) The velocity of an oscillating charge as it moves to and fro along a wire is always a. constant b. zero c. changing d. infinite
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25) Which one of following band is completely filled in case of conductors? a. Conduction band b. Fermi band c. Valence band d. Forbidden band
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26) Which one of the following has the greatest energy gap? a. insulator b. conductor c. semi conductor d. any of above
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27) The value of resistivity for insulator is of the order of a. 105 ohm metre b. 106 ohm metre c. 107 ohm metre d. 108 ohm metre
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28) Thermions are a. protons b. positrons c. electrons d. photons
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29) Hole is equivalent to a. a negative charge b. a positive charge c. a neutral particle d. an electron
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30) Which one of the following is not a donor impurity? a. antimony b. phosphorus c. aluminium d. arsenic
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31) Forward current through a semi conductor diode circuit is due to a. minority carriers b. majority carriers c. holes d. electrons
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32) In the transistor schematic symbol, the arrow a. is located on the emitter b. is located on the base c. is locate on the collector d. points form north to south
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33) In full wave rectification the output D.C. voltage across the load is obtained for a. The positive half cycle of input A.C. b. The negative half cycle of input A.C. c. The complete cycle of input A.C. d. All of the above.
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34) The semiconductor diode can be used as a rectifier because a. It has low resistance to the current flow when forward biased & high resistance when reverse biased. b. It has low resistance to the current flow when forward biased. c. It has high resistance to the current flow when reverse biased d. Its conductivity increases with rise of temperature.
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35) In half-wave rectification the output D.C. voltages is obtained across the load for a. The negative half cycle of A.C. b. The positive half cycle of A.C. c. The positive and negative half cycles d. Either positive or negative half of A.C.
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36) The device or circuit used for conversion of A.C. into D.C. is called a. An amplifier. b. A rectifier c. Filtering circuit d. Converter.
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37) The device used for conversion of D.C. to A.C. is called a. Converter b. A rectifier c. Inverter d. Oscillator
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38) The especially designed semiconductor diodes used as indicator lamps in electronic circuits are a. The switch b. The light emitting diode c. The photo diodes d. Solar cells
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39) The specially designed semi-conductor diodes used as fast counters in electronic circuits are a. The light emitting diodes b. Photo diodes c. Photo voltaic cell d. Solar cells
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40) The alternating voltage is an example of a. A digital waveform b. An analogue waveform c. Discrete waveform d. None at all
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