Q.94 A device whose characteristics are very close to that of an ideal current source is (A) a gas diode. (B) a BJT in CB mode. (C) a BJT in CE mode. (D) a triode. Ans: C
Q.95 In an N-type semiconductor, the concentration of minority carriers mainly depends upon (A) the doping technique. (B) the number of donor atoms. (C) the temperature of the material (D) the quality of the intrinsic material, Ge or Si.
Ans: B
Q.96 When forward bias is applied to a junction diode, it (A) increases the potential barrier. (B) decreases the potential barrier. (C) reduces the majority-carrier current to zero. (D) reduces the minority-carrier current to zero.
Ans: B
Q.97 The theoretical maximum efficiency of a Bridge rectifier circuit is (A) 48.2%. (B) 81.2%. (C) 82%. (D) 40.6%.
Ans: B
Q.98 The input resistance of a common-collector configuration will be of the order of (A) Ω K~ 90 (B) Ω K~ 60 (C) Ω 0K~ 15 (D) Ω 0K30 and above
Ans: D
Q.99 A switching voltage regulator can be of the following type: (A) step-down (B) step-up (C) inverting (D) none of these
Ans: A
Q.100 A UJT contains (A) four pn junctions (B) three pn junctions (C) two pn junctions (D) one pn junction
Ans: D
Q.101 The foundation on which an IC is built is called
(A) an insulator. (B) a base. (C) a wafer. (D) a plate.
Ans: C
Q.102 X-ray tubes make use of (A) Thermionic emission. (B) Secondary emission. (C) High field emission. (D) Photoelectric emission.
Ans: C
Q.103 Which of the following components are all active components? (A) A resistor and a capacitor. (B) A microphone, a LCD and a Thyratron. (C) An electric bulb, a transformer and a varactor diode. (D) An SCR, a vacuum diode and an LED. Ans: D
Q.104 Doping materials are called impurities because they (A) Decrease the number of charge carriers. (B) Change the chemical properties of semiconductors. (C) Make semiconductors less than 100 percent pure. (D) Alter the crystal structures of the pure semiconductors. Ans: B
Q.105 Avalanche breakdown is primarily dependent on the phenomenon of (A) Collision (B) Doping (C) Ionisation (D) Recombination Ans: D
Q.106 In a rectifier, larger the value of shunt capacitor filter (A) Larger the peak-to-peak value of ripple voltage. (B) Larger the peak current in the rectifying diode. (C) Longer the time that current pulse flows through the diode. (D) Smaller the dc voltage across the load.
Ans: D
Q.107 The main reason why electrons can tunnel through a P-N junction is that (A) They have high energy. (B) Barrier potential is very low. (C) Depletion layer is extremely thin. (D) Impurity level is low.
Ans: C
Q.108 If a change in base current does not change the collector current, the transistor amplifier is said to be (A) Saturated. (B) Cut-off. (C) Critical. (D) Complemented.
Ans: A
Q.109 The extremely high input impedance of a MOSFET is primarily due to the (A) Absence of its channel. (B) Negative gate-source voltage. (C) Depletion of current carriers. (D) Extremely small leakage current of its gate capacitor.
Ans: A
Q.110 After firing an SCR, the gating pulse is removed. The current in the SCR will (A) Remains the same. (B) Immediately fall to zero. (C) Rise up. (D) Rise a little and then fall to zero.
Ans: A
Q.111 An inverting operational amplifier has Ω = 2MR f and Ω = 2KR 1 . Its scale factor is
(A) 1000. (B) 1000 − . (C) 3 10 − . (D) 3 10 −− .
Ans: B
Q.112 In the context of IC fabrication, metallisation means (A) Connecting metallic wires. (B) Forming interconnecting conduction pattern and bonding pads. (C) Depositing 2 Sio layer. (D) Covering with a metallic cap.
Ans: B
Q.113 The colour band sequence of a resistor is yellow, violet, orange and gold. The range in which its value must lie so as to satisfy the tolerance specified is between (A) Ω K40 and Ω K5.42 (B) Ω 65.44 and Ω 3.49 (C) Ω K65.44 and Ω K35.49 (D) Ω K25.43 and Ω K22.45 Ans: D
Q.114 A device whose characteristics are very close to that of an ideal voltage source is (A) a vaccum diode. (B) a DIAC. (C) a zener diode. (D) a FET. Ans: C
Q.115 The forbidden energy gap in semiconductors (A) lies just below the valance band (B) lies just above the conduction band (C) lies between the valence band and the conduction band (D) is the same as the valence band Ans: C
Q.116 The barrier potential for a Ge PN junction is (A) 0.6V. (B) 0.3V. (C) 0.1V. (D) 0.5V.
Ans: B
Q.117 The ripple factor of a power supply is a measure of (A) its voltage regulation. (B) its diode rating. (C) purity of power output. (D) its filter efficiency.
Ans: C
Q.118 In a BJT, if the emitter junction is reverse-biased and the collector junction is reverse-biased, it is said to operate in (A) in active region (B) in saturation region (C) in cut-off region (D) none of the above
Ans: C
Q.119 In the switching type of voltage regulators, the power efficiency will be of the order of (A) 50% or less. (B) 60%. (C) 40% or more. (D) 90% or more. Ans: D
Q.120 The resistance between bases of a UJT is typically in the range of (A) 2 to 3 KΩ (B) 5 to 10 KΩ (C) 15 to 20 KΩ (D) 18 to 20 KΩ
Ans: B
Q.121 The quantity that serves as a figure of merit for a DIFF AMP is (A) slew rate. (B) bandwidth. (C) input bias current. (D) CMRR.
Ans: D
Q.122 Practical range of resistance values obtainable with base diffused resistors is
(A) 10 Ω to 1 KΩ (B) 20 Ω to 30 KΩ (C) 5 Ω to 3 KΩ (D) 20KΩ to 50 KΩ
Ans: D
Q.123 The colour band sequence of a resistor is Yellow, Violet, Orange and Gold. The range in which its value must lie so as to satisfy the tolerance specified is between (A) Ω K.6644 and Ω K.3549 (B) .65 44 Ω K and .35 49 Ω K (C) Ω K.6544 and Ω K.3649 (D) Ω K45 and Ω K.3449 Ans: B
Q.124 With increasing temperature, the resistivity of an intrinsic semiconductor decreases. This is because, with the increase of temperature (A) The carrier concentration increases but the mobility of carriers decreases. (B) Both the carrier concentration and mobility of carriers decreases. (C) The carrier concentration decreases, but the mobility of carriers increases. (D) The carrier concentration remains the same but the mobility of carriers decreases. Ans: A
Q.125 At room temperature of 25ºC, the barrier Potential for Silicon is 0.7V. Its value at 0ºC will be (A) 0.7 V. (B) 0.65 V. (C) 0.75 V. (D) 0.55 V. Ans: C
Q.126 Which of the following is a unipolar device? (A) P-N junction diode (B) Zener diode (C) Tunnel diode (D) Schottky diode
Ans: D
Q.127 On applying a Positive voltage signal to the base of a normally biased N-P-N CE transistor amplifier (A) Base current will fall. (B) Collector current will fall. (C) Emitter current will fall. (D) Collector voltage will become less positive.
Ans: D
Q.128 An N-channel JFET has Pinch-off Voltage of VP = – 4V and given that VGS = –1V, then the minimum VDS for the device to operate in the Pinch-off region will be (A) +1V (B) +3V (C) +4V (D) +5V
Ans: B
Q.129 The extremely high input impedance of a MOSFET is Primarily because of (A) Absence of its channel (B) Depletion of current carriers (C) Extremely small leakage current of its gate capacitor (D) Negative VGS
Ans: A
Q.130 When two identical SCRs are placed back-to-back in series with a load and if each is fired at 90º, then the voltage across the load will be
(A) Peak Voltage 2 × π
(B) Zero
(C) Peak Voltage 1 × π
(D) Peak Voltage 2 1 ×
Ans: A
Q.131 In the differentiating circuit shown in Fig.1, the function of resistor R1 is to
(A) Enable the circuit to approach ideal differentiator (B) Maintain high input impedance (C) Eliminate high frequency noise spikes (D) Prevent oscillations at high frequencies Ans:C
Q.95 In an N-type semiconductor, the concentration of minority carriers mainly depends upon (A) the doping technique. (B) the number of donor atoms. (C) the temperature of the material (D) the quality of the intrinsic material, Ge or Si.
Ans: B
Q.96 When forward bias is applied to a junction diode, it (A) increases the potential barrier. (B) decreases the potential barrier. (C) reduces the majority-carrier current to zero. (D) reduces the minority-carrier current to zero.
Ans: B
Q.97 The theoretical maximum efficiency of a Bridge rectifier circuit is (A) 48.2%. (B) 81.2%. (C) 82%. (D) 40.6%.
Ans: B
Q.98 The input resistance of a common-collector configuration will be of the order of (A) Ω K~ 90 (B) Ω K~ 60 (C) Ω 0K~ 15 (D) Ω 0K30 and above
Ans: D
Q.99 A switching voltage regulator can be of the following type: (A) step-down (B) step-up (C) inverting (D) none of these
Ans: A
Q.100 A UJT contains (A) four pn junctions (B) three pn junctions (C) two pn junctions (D) one pn junction
Ans: D
Q.101 The foundation on which an IC is built is called
(A) an insulator. (B) a base. (C) a wafer. (D) a plate.
Ans: C
Q.102 X-ray tubes make use of (A) Thermionic emission. (B) Secondary emission. (C) High field emission. (D) Photoelectric emission.
Ans: C
Q.103 Which of the following components are all active components? (A) A resistor and a capacitor. (B) A microphone, a LCD and a Thyratron. (C) An electric bulb, a transformer and a varactor diode. (D) An SCR, a vacuum diode and an LED. Ans: D
Q.104 Doping materials are called impurities because they (A) Decrease the number of charge carriers. (B) Change the chemical properties of semiconductors. (C) Make semiconductors less than 100 percent pure. (D) Alter the crystal structures of the pure semiconductors. Ans: B
Q.105 Avalanche breakdown is primarily dependent on the phenomenon of (A) Collision (B) Doping (C) Ionisation (D) Recombination Ans: D
Q.106 In a rectifier, larger the value of shunt capacitor filter (A) Larger the peak-to-peak value of ripple voltage. (B) Larger the peak current in the rectifying diode. (C) Longer the time that current pulse flows through the diode. (D) Smaller the dc voltage across the load.
Ans: D
Q.107 The main reason why electrons can tunnel through a P-N junction is that (A) They have high energy. (B) Barrier potential is very low. (C) Depletion layer is extremely thin. (D) Impurity level is low.
Ans: C
Q.108 If a change in base current does not change the collector current, the transistor amplifier is said to be (A) Saturated. (B) Cut-off. (C) Critical. (D) Complemented.
Ans: A
Q.109 The extremely high input impedance of a MOSFET is primarily due to the (A) Absence of its channel. (B) Negative gate-source voltage. (C) Depletion of current carriers. (D) Extremely small leakage current of its gate capacitor.
Ans: A
Q.110 After firing an SCR, the gating pulse is removed. The current in the SCR will (A) Remains the same. (B) Immediately fall to zero. (C) Rise up. (D) Rise a little and then fall to zero.
Ans: A
Q.111 An inverting operational amplifier has Ω = 2MR f and Ω = 2KR 1 . Its scale factor is
(A) 1000. (B) 1000 − . (C) 3 10 − . (D) 3 10 −− .
Ans: B
Q.112 In the context of IC fabrication, metallisation means (A) Connecting metallic wires. (B) Forming interconnecting conduction pattern and bonding pads. (C) Depositing 2 Sio layer. (D) Covering with a metallic cap.
Ans: B
Q.113 The colour band sequence of a resistor is yellow, violet, orange and gold. The range in which its value must lie so as to satisfy the tolerance specified is between (A) Ω K40 and Ω K5.42 (B) Ω 65.44 and Ω 3.49 (C) Ω K65.44 and Ω K35.49 (D) Ω K25.43 and Ω K22.45 Ans: D
Q.114 A device whose characteristics are very close to that of an ideal voltage source is (A) a vaccum diode. (B) a DIAC. (C) a zener diode. (D) a FET. Ans: C
Q.115 The forbidden energy gap in semiconductors (A) lies just below the valance band (B) lies just above the conduction band (C) lies between the valence band and the conduction band (D) is the same as the valence band Ans: C
Q.116 The barrier potential for a Ge PN junction is (A) 0.6V. (B) 0.3V. (C) 0.1V. (D) 0.5V.
Ans: B
Q.117 The ripple factor of a power supply is a measure of (A) its voltage regulation. (B) its diode rating. (C) purity of power output. (D) its filter efficiency.
Ans: C
Q.118 In a BJT, if the emitter junction is reverse-biased and the collector junction is reverse-biased, it is said to operate in (A) in active region (B) in saturation region (C) in cut-off region (D) none of the above
Ans: C
Q.119 In the switching type of voltage regulators, the power efficiency will be of the order of (A) 50% or less. (B) 60%. (C) 40% or more. (D) 90% or more. Ans: D
Q.120 The resistance between bases of a UJT is typically in the range of (A) 2 to 3 KΩ (B) 5 to 10 KΩ (C) 15 to 20 KΩ (D) 18 to 20 KΩ
Ans: B
Q.121 The quantity that serves as a figure of merit for a DIFF AMP is (A) slew rate. (B) bandwidth. (C) input bias current. (D) CMRR.
Ans: D
Q.122 Practical range of resistance values obtainable with base diffused resistors is
(A) 10 Ω to 1 KΩ (B) 20 Ω to 30 KΩ (C) 5 Ω to 3 KΩ (D) 20KΩ to 50 KΩ
Ans: D
Q.123 The colour band sequence of a resistor is Yellow, Violet, Orange and Gold. The range in which its value must lie so as to satisfy the tolerance specified is between (A) Ω K.6644 and Ω K.3549 (B) .65 44 Ω K and .35 49 Ω K (C) Ω K.6544 and Ω K.3649 (D) Ω K45 and Ω K.3449 Ans: B
Q.124 With increasing temperature, the resistivity of an intrinsic semiconductor decreases. This is because, with the increase of temperature (A) The carrier concentration increases but the mobility of carriers decreases. (B) Both the carrier concentration and mobility of carriers decreases. (C) The carrier concentration decreases, but the mobility of carriers increases. (D) The carrier concentration remains the same but the mobility of carriers decreases. Ans: A
Q.125 At room temperature of 25ºC, the barrier Potential for Silicon is 0.7V. Its value at 0ºC will be (A) 0.7 V. (B) 0.65 V. (C) 0.75 V. (D) 0.55 V. Ans: C
Q.126 Which of the following is a unipolar device? (A) P-N junction diode (B) Zener diode (C) Tunnel diode (D) Schottky diode
Ans: D
Q.127 On applying a Positive voltage signal to the base of a normally biased N-P-N CE transistor amplifier (A) Base current will fall. (B) Collector current will fall. (C) Emitter current will fall. (D) Collector voltage will become less positive.
Ans: D
Q.128 An N-channel JFET has Pinch-off Voltage of VP = – 4V and given that VGS = –1V, then the minimum VDS for the device to operate in the Pinch-off region will be (A) +1V (B) +3V (C) +4V (D) +5V
Ans: B
Q.129 The extremely high input impedance of a MOSFET is Primarily because of (A) Absence of its channel (B) Depletion of current carriers (C) Extremely small leakage current of its gate capacitor (D) Negative VGS
Ans: A
Q.130 When two identical SCRs are placed back-to-back in series with a load and if each is fired at 90º, then the voltage across the load will be
(A) Peak Voltage 2 × π
(B) Zero
(C) Peak Voltage 1 × π
(D) Peak Voltage 2 1 ×
Ans: A
Q.131 In the differentiating circuit shown in Fig.1, the function of resistor R1 is to
(A) Enable the circuit to approach ideal differentiator (B) Maintain high input impedance (C) Eliminate high frequency noise spikes (D) Prevent oscillations at high frequencies Ans:C
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