Engineering

ISBT Reasoning for all banking PO,Clerk,IBPS PO,Railway,SSC,IAS,OAS Exams

Q61.
A power gain of 30dB is equivalent to which amplification factor ?
1) 0.001 2) 1/30
3) 30 4) 1000
5)None of these
Answer : 1000
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Q62.
A disadvantage of a half wave rectifier is the fact that - 
1) The output voltage is excessive compared to that of a full-wave rectifier 2) The output current is excessive compared to that of a full-wave rectifier.
3) The output waveform is harder to filter than is the case with a full wave rectifier 4) It requires several expensive diodes, whereas a full wave rectifier requires only a single diode
5)None of these
Answer : The output waveform is harder to filter than is the case with a full wave rectifier
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Q63.
In N-type semiconductor, the minority carriers are -
1) Electrons 2) Protons
3) Holes 4) Positrons
5)None of these
Answer : Holes
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Q64.
The VA rating of a transformer is an expression of - 
1) The maximum frequency at which it can function 2) The type of core material it has
3) The voltage step-up or step-down ratio 4) The impedance transfer ratio
5)None of the above
Answer : None of the above
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Q65.
When the bias in an FET stops the flow of current, the condition is called -
1) Forward breakover 2) Cutoff
3) Reverse bias 4) Pinchoff
5)Avalanche
Answer : Pinchoff
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Q66.
The other name for beta of BJT is
1) Current amplification factor 2) Voltage amplification factor
3) Power amplification factor 4) Optimum amplification frequency
5)None of these
Answer : Current amplification factor
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Q67.
Which of the following is not characteristic of an oscillator ?
1) Negative feedback 2) Good output to input coupling
3) Reasonably high transistor gain 4) Alternating current signal output
5)Usefulness as a signal generator
Answer : Negative feedback
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Q68.
A very brief, high voltage spike on an ac power line is called as - 
1) A bleeder 2) An arc
3) A transient 4) An avalanche
5)A clipped peak
Answer : A transient
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Q69.
Which of the following is not a common form of data transmission ?
1) Polarization modulation 2) Frequency modulation
3) Amplitude modulation 4) Phase modulation
5)Pulse modulation
Answer : Polarization modulation
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Q70.
A diode can be used as a frequency multiplier because of its - 
1) Junction capacitance 2) Non linearity
3) Avalanche voltage 4) Forward breakover
5)Charge carrier concentration
Answer : Non linearity
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