DC POWER SUPPLIES

Objective Questions

Short notes

Objective questions (Answers are given below)

  1. The ripple factor of a power supply is a
    measure of
    (a) its filter efficiency
    (b) its voltage regulation
    (c) diode rating
    (d) purity of power output.
  2. The basic reason why a FW rectifier has
    twice the efficiency of a HW rectifier is that
    (a) it makes use of a transformer
    (b) its ripple factor is much less
    (c) it utilizes both half-cycle of the input
    (d) its output frequency is double the line
    frequency.
  3. The output of a half-wave rectifier is suitable
    only for
    (a) running car radios
    (b) running ac motors
    (c) charging batteries
    (d) running tape-recorders.
  4. The ripple factor of a bridge rectifier is
    (a) 0.406 (b) 0.812
    (c) 1.21 (d) 1.11
  1. The ripple factor of a power suply is given
    by (symobls have the usual meaning).
    (a) (b) (c)
  2. The PIV of a half-wave rectifier circuit with
    a shunt capacitor filter is
    (a) 2 Vsm (b) Vsm
    (c) Vsm/2 (d) 3 Vsm.
  3. The primary function of a rectifier filter is
    to
    (a) minimise ac input variations
    (b) suppress odd harmonics in the rectifier
    output
    (c) stabilise dc level of the output voltage
    (d) remove ripples from the rectified output
  4. In a rectifier, larger the value of shunt
    capacitor filter
    (a) larger the p-p value of ripple voltage
    (b) larger the peak current in the recti- fying
    diode
    (c) longer the time that current pulse flows
    through the diode
    (d) smaller the dc voltage across the load.
  5. In a LC filter, the ripple factor,
    (a) increases with the load current
    (b) increases with the load resistance
    (c) remains constant with the load current
    (d) has the lowest value.
  6. The main reason why a bleeder resistor is
    used in a dc power supply is that it
    (a) keeps the supply ON
    (b) improves voltage regulation
    (c) improves filtering action
    (d) both (b) and (c).
  7. Which stage of a dc power supply uses a
    Zener as the main component?
    (a) rectifier (b) voltage divider
    (c) regulator (d) filter.
  8. Which rectifier requires four diodes ?
    (a) half-wave voltage doubler
    (b) full-wave voltage doubler
    (c) full-wave bridge circuit
    (d) voltage quadrupler.
  9. For a half-wave controlled rectifier, the average
    value of output dc voltage is given by
    (a) Vdc =
    2
    m V
    π
    (1 − cos θ1)
    (b) Vdc =
    2 m V
    π
    (1 + cos θ1)
    (c) Vdc = m V
    π
    (cos θ1 − 1)
    (d) Vdc =
    2
    m V
    π
    (cos θ1 + 1).
  10. If, by mistake, ac source in a bridge rectifier
    is connected across the dc termi- nals, it
    will burn out and hence short …….. diodes.
    (a) one (b) two
    (c) three (d) four.
  1. (a) 2. (c) 3. (b) 4. (c) 5. (b) 6. (a) 7. (d) 8. (b) 9. (c) 10. (d) 11. (c) 12.(b) 13. (c) 14. (d)

Visit Here for other basic electrical engineering MCQ and Notes

ELECTRIC CURRENT AND OHM’S LAW- Questions, MCQ and Short notes

DC NETWORK THEOREMS- Questions, MCQ and Short notes

WORK, POWER AND ENERGY- Questions, MCQ and Short notes

ELECTROSTATICS- Questions, MCQ and Short notes

CAPACITANCE- Questions, MCQ and Short notes

MAGNETISM AND ELECTROMAGNETISM- Questions, MCQ and Short notes

ELECTROMAGNETIC INDUCTION- Questions, MCQ and Short notes

MAGNETIC HYSTERESIS- Questions, MCQ and Short notes

ELECTROCHEMICAL POWER SOURCES- Questions, MCQ and Short notes

ELECTRICAL INSTRUMENTS AND MEASUREMENTS- Questions, MCQ and Short notes

A.C. FUNDAMENTALS- Questions, MCQ and Short notes

COMPLEX NUMBERS- Questions, MCQ and Short notes

SERIES A.C. CIRCUITS- Questions, MCQ and Short notes

PARALLEL A.C. CIRCUITS- Questions, MCQ and Short notes

A.C. NETWORK ANAYLSIS- Questions, MCQ and Short notes

A.C. BRIDGES- Questions, MCQ and Short notes

A.C. FILTER NETWORKS- Questions, MCQ and Short notes

CIRCLE DIAGRAMS- Questions, MCQ and Short notes

POLYPHASE CIRCUITS- Questions, MCQ and Short notes

HARMONICS- Questions, MCQ and Short notes

FOURIER SERIES- Questions, MCQ and Short notes

TRANSIENTS- Questions, MCQ and Short notes

SYMMETRICAL COMPONENTS- Questions, MCQ and Short notes

INTRODUCTION TO ELECTRICAL ENERGY GENERATION- Questions, MCQ and Short notes

ELEMENTS OF ELECTROMECHANICAL ENERGY CONVERSION- Questions, MCQ and Short notes

D.C. GENERATORS- Questions, MCQ and Short notes

ARMATURE REACTION AND COMMUTATION- Questions, MCQ and Short notes

GENERATOR CHARACTERISTICS- Questions, MCQ and Short notes

D.C. MOTOR- Questions, MCQ and Short notes

SPEED CONTROL OF D.C. MOTORS- Questions, MCQ and Short notes

TESTING OF D.C. MACHINES- Questions, MCQ and Short notes

TRANSFORMER- Questions, MCQ and Short notes

TRANSFORMER: THREE PHASE- Questions, MCQ and Short notes

INDUCTION MOTOR- Questions, MCQ and Short notes

COMPUTATIONS AND CIRCLE DIAGRAMS- Questions, MCQ and Short notes

SINGLE-PHASE MOTORS- Questions, MCQ and Short notes

ALTERNATORS- Questions, MCQ and Short notes

SYNCHRONOUS MOTOR- Questions, MCQ and Short notes

SPECIAL MACHINES- Questions, MCQ and Short notes

D.C. TRANSMISSION AND DISTRIBUTION- Questions, MCQ and Short notes

A.C. TRANSMISSION AND DISTRIBUTION- Questions, MCQ and Short notes

DISTRIBUTION AUTOMATION- Questions, MCQ and Short notes

ELECTRIC TRACTION- Questions, MCQ and Short notes

INDUSTRIAL APPLICATIONS OF ELECTRIC MOTORS- Questions, MCQ and Short notes

RATING AND SERVICE CAPACITY- Questions, MCQ and Short notes

ELECTRONIC CONTROL OF A.C. MOTORS- Questions, MCQ and Short notes

ELECTRIC HEATING- Questions, MCQ and Short notes

ELECTRIC WELDING- Questions, MCQ and Short notes

ILLUMINATION- Questions, MCQ and Short notes

TARIFFS AND ECONOMIC CONSIDERATIONS- Questions, MCQ and Short notes

SEMICONDUCTOR PHYSICS- Questions, MCQ and Short notes

P-N JUNCTION DIODE- Questions, MCQ and Short notes

OPTOELECTRONIC DEVICES- Questions, MCQ and Short notes

SPECIAL DIODES- Questions, MCQ and Short notes

DC POWER SUPPLIES- Questions, MCQ and Short notes

REGULATED POWER SUPPLY- Questions, MCQ and Short notes

BIPOLAR JUNCTION TRANSISTOR- Questions, MCQ and Short notes

LOAD LINES AND DC BIAS CIRCUITS- Questions, MCQ and Short notes

TRANSISTOR EQUIVALENT CIRCUITS AND MODELS- Questions, MCQ and Short notes

SINGLESTAGE TRANSISTOR AMPLIFIERS- Questions, MCQ and Short notes

MULTISTAGE AND FEEDBACK AMPLIFIERS- Questions, MCQ and Short notes

FEEDBACK AMPLIFIER- Questions, MCQ and Short notes

FIELD EFFECT TRANSISTORS- Questions, MCQ and Short notes

BREAKDOWN DEVICES- Questions, MCQ and Short notes

SINUSOIDAL AND NONSINUSOIDAL OSCILLATORS- Questions, MCQ and Short notes

MODULATION AND DEMODULATION- Questions, MCQ and Short notes

INTEGRATED CIRCUITS- Questions, MCQ and Short notes

OP-AMP AND ITS APPLICATIONS- Questions, MCQ and Short notes

NUMBER SYSTEMS AND CODES- Questions, MCQ and Short notes

LOGIC GATES- Questions, MCQ and Short notes

BOOLEAN ALGEBRA AND LOGIC FAMILIES- Questions, MCQ and Short notes

FLIP-FLOPS AND RELATED DEVICES- Questions, MCQ and Short notes

ELECTRONIC INSTRUMENTS- Questions, MCQ and Short notes

Leave a Reply