MCQ தேர்வு

Q1
Which logic family generally offers the lowest static power dissipation?
Q2
The power factor of a synchronous motor can be controlled by varying its:
Q3
A DC series motor should never be operated without mechanical load because:
Q4
Which test on a transformer is primarily used to determine core loss?
Q5
For a symmetrical three-phase fault, the negative and zero sequence currents are:
Q6
Which motor is preferred where high starting torque and variable speed are required?
Q7
The slip of an induction motor operating at 1440 rpm on a 50 Hz, four-pole supply is:
Q8
The quality factor of a series RLC circuit at resonance is:
Q9
The resolution of an ideal n-bit ADC expressed as a fraction of full-scale range is approximately:
Q10
An overexcited synchronous motor operates at:
Q11
In a DC machine, armature reaction mainly causes:
Q12
The rotor frequency of an induction motor operating at slip s and supply frequency f is:
Q13
The Barkhausen criterion for sustained oscillation requires the loop gain to satisfy:
Q14
The skin effect in a conductor causes:
Q15
In a synchronous generator, the frequency of generated emf is determined primarily by:
Q16
In an ideal voltage-source inverter, the output voltage waveform is fundamentally controlled by:
Q17
A common-emitter BJT amplifier provides a phase shift between input and output of approximately:
Q18
In a power system, the primary purpose of reactive power compensation using shunt capacitors is to:
Q19
In a transformer, the maximum efficiency occurs when:
Q20
Which power electronic device can be turned OFF by a gate signal under normal operation?
Q21
For maximum power transfer in an AC circuit, the load impedance should be:
Q22
For a single line-to-ground fault, the positive, negative and zero sequence networks are connected:
Q23
For an overhead transmission line, corona loss increases significantly with:
Q24
The synchronous speed of a 6-pole, 50 Hz induction motor is:
Q25
The Ferranti effect becomes significant in:
Q26
The primary purpose of the Buchholz relay in an oil-immersed transformer is to detect:
Q27
The crawling phenomenon in an induction motor is mainly associated with:
Q28
A three-phase induction motor draws 20 A at 0.8 power factor from a 400 V supply. Its approximate active input power is:
Q29
In a capacitor-input filter, increasing the capacitance generally causes the ripple voltage to:
Q30
Aliasing in an ADC occurs when the sampling frequency is:
Q31
A 50 Hz transformer has a maximum flux of 0.01 Wb and 100 turns in its primary winding. What is the approximate RMS induced emf?
Q32
The primary function of a circuit breaker is to:
Q33
In a balanced Wheatstone bridge, the galvanometer current is:
Q34
Bundled conductors in EHV transmission lines are mainly used to:
Q35
In a MOSFET, the gate current under steady-state DC operation is ideally:
Q36
The per-unit impedance of a transformer is independent of:
Q37
Which relay is commonly used for protection of long high-voltage transmission lines?
Q38
Which starting method provides the highest starting torque for a slip-ring induction motor?
Q39
The main purpose of earthing electrical equipment is to:
Q40
At resonance in a series RLC circuit, the impedance is:
Q41
PWM inverters are primarily used to:
Q42
In a phase-locked loop, the VCO frequency is controlled by:
Q43
A CT secondary should never be open-circuited while its primary is energized because:
Q44
In a buck converter operating in continuous conduction mode, the ideal output voltage is:
Q45
For an ideal boost converter operating in continuous conduction mode, the output voltage is:
Q46
For an ideal op-amp operating with negative feedback, the voltage difference between its input terminals is approximately:
Q47
The ripple frequency of a three-phase full-wave bridge rectifier supplied from a 50 Hz source is:
Q48
In a DC generator, the commutator primarily acts as:
Q49
A 10 kVA, 200/400 V transformer has a full-load secondary current of:
Q50
For a three-phase balanced star-connected load, if the phase voltage is 230 V, what is the line voltage?
Q51
The reach of a distance relay is primarily determined by:
Q52
The cogging phenomenon in an induction motor occurs mainly due to:
Q53
In a DC shunt motor, which condition primarily causes the motor speed to increase dangerously?
Q54
Which semiconductor material has the widest band gap among the following?
Q55
The characteristic impedance of a lossless transmission line is determined by:
Q56
The condition for maximum power transfer from a DC source to a resistive load is: