721 An OP-AMP comparator is a circuit that compares the signal voltage on one of its inputs with a ______________? Physics Medium Full question → A Non-inverting voltage at output B Reference voltage on the other C Virtual input D Output
722 Non-inverting amplifier circuits have____________? Physics Medium Full question → A A very high input impedance B A very low input impedance C A low output impedance D None of the above
723 The operation of a transistor requires______________? Physics Medium Full question → A That the emitter be heated B That the base be heated C That the collector be heated D None of the above
724 To obtain an n-type semiconductor germanium crystal it must be doped with foreign atoms whose valency is_____________? Physics Medium Full question → A 2 B 3 C 4 D 5
725 The operational amplifier is______________? Physics Medium Full question → A A high gain amplifier B A high-power amplifier C A high resistance amplifier D A low resistance amplifier
726 The alternating voltage is an example of_______________? Physics Medium Full question → A A digital waveform B An analogue waveform C Discrete waveform D None at all
727 The specially designed semi-conductor diodes used as fast counters in electronic circuits are______________? Physics Medium Full question → A The light emitting diodes B Photo diodes C Photo voltaic cell D Solar cells.
728 The device used for conversion of D.C. to A.C. is called______________? Physics Medium Full question → A Converter B A rectifier C Inverter D Oscillator
729 In half-wave rectification the output D.C. voltages is obtained across the load for_______________? Physics Medium Full question → 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.
730 In full wave rectification the output D.C. voltage across the load is obtained for_____________? Physics Medium Full question → 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.
731 In the transistor schematic symbol, the arrow______________? Physics Medium Full question → A is located on the emitter B is located on the base C is locate on the collector D points form north to south
732 Which one of the following is not a donor impurity ? Physics Medium Full question → A antimony B phosphorus C aluminium D arsenic
733 Forward current through a semi conductor diode circuit is due to____________? Physics Medium Full question → A minority carriers B majority carriers C holes D electron
734 The value of resistivity for insulator is of the order of____________? Physics Medium Full question → A 105 ohm metre B 106 ohm metre C 107 ohm metre D 108 ohm metre
735 Which one of following band is completely filled in case of conductors ? Physics Medium Full question → A Conduction band B Fermi band C Valence band D Forbidden band
736 Depletion region of a junction is formed_____________? Physics Medium Full question → A during the manufacturing process B under forward bias C under reverse bias D when temperature varies
737 The simplest type of rectification known as half wave rectification is obtained by____________________? Physics Medium Full question → 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
738 In p-n-p transistor the collector current is________________? Physics Medium Full question → A equal to emitter current B slightly less than emitter current C greater than emitter current D any of above
739 How many electrons per second constitute a current of one micro ampere? Physics Medium Full question → A one electron B 10 –6 electrons C 10 6 electrons D 6.25 × 1012 electrons
740 A piece of copper and a piece of germanium are cooled from the room temperature down to 77 K. Physics Medium Full question → A The resistance of each of them increases. B The resistance of each of them decreases. C The resistance of copper decreases and that of germanium increases. D The resistance of copper increases and that of germanium decreases