MCQOPTIONS
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MCQOPTIONS
This section includes 114 Mcqs, each offering curated multiple-choice questions to sharpen your 12th knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
Points to be considered in choosing a capacitor |
| A. | Working voltage |
| B. | Type of dielectric |
| C. | Capacitance |
| D. | All of the above |
| Answer» E. | |
| 52. |
Effects of capacitance |
| A. | It opposes any change in the amount of voltage |
| B. | B Voltage is lagged behind the current by a quarter cycle |
| C. | Electric energy is stored in the capacitor in the form of electrostatic field |
| D. | All of the above |
| Answer» E. | |
| 53. |
A series RLCcircuit consists of a 10 resistor in series with L = 10 Ha and C= 100 F. Determine a new value of Ia for which the resonant frequency is one �half the original value. |
| A. | 40 H |
| B. | 40 mH |
| C. | 40 pH |
| D. | 40 nH |
| Answer» B. 40 mH | |
| 54. |
What capacitance exists not through design but simply because two conducting surfaces are relatively close to each other? |
| A. | Surge |
| B. | Stray |
| C. | Natural |
| D. | Normal |
| Answer» C. Natural | |
| 55. |
What is the reading of an ohmmeter for a shorted capacitor? |
| A. | Zero |
| B. | Infinity |
| C. | k |
| D. | M |
| Answer» B. Infinity | |
| 56. |
An open inductor has |
| A. | Zero resistance and infinite inductance |
| B. | B Infinite resistance and zero inductance |
| C. | C Infinite resistance and infinite inductance |
| D. | D Zero resistance and zero inductance |
| Answer» C. C Infinite resistance and infinite inductance | |
| 57. |
What rating of a resistor determines its ability to absorb heat? |
| A. | Wattage |
| B. | Ohmic |
| C. | Current |
| D. | Voltage |
| Answer» B. Ohmic | |
| 58. |
Which one of the following elements serves as a protection against overload? |
| A. | Fuse |
| B. | Switch |
| C. | Resistor |
| D. | Relay |
| Answer» B. Switch | |
| 59. |
What is the half-power bandwidth of a parallel resonant circuit which has a resonant frequency of 3.6 MHz and Q of 218? |
| A. | 1.65 kHz |
| B. | 16.5 MHz |
| C. | 16.5 kHz |
| D. | 165 kHz |
| Answer» D. 165 kHz | |
| 60. |
The voltage lags the current by cycle in a |
| A. | Purely resistive circuit |
| B. | Purely inductive circuit |
| C. | Purely capacitive circuit |
| D. | Circuit containing resistancea capacitance and inductance |
| Answer» D. Circuit containing resistancea capacitance and inductance | |
| 61. |
If two equal resistances connected in series across a certain supply are now connected in parallel across the same supplya the power produced will be _____ that of series connection |
| A. | One-half |
| B. | One-fourth |
| C. | Two times |
| D. | Four times |
| Answer» E. | |
| 62. |
At what frequency will the current in a series RLCcircuit reach its maximum value for an applied voltage of 15 V with R = 500 a L = 100 H and C= 0.001 F? |
| A. | 503 kHz |
| B. | 403 kHz |
| C. | 603 kHz |
| D. | 303 kHz |
| Answer» B. 403 kHz | |
| 63. |
The value of temperature coefficient ( ) is dependent upon |
| A. | The nature of material and temperature |
| B. | The length of material |
| C. | The cross-sectional area of the material |
| D. | The volume of the material |
| Answer» B. The length of material | |
| 64. |
An intermittent and non-symmetrical alternating current like that obtained from the secondary winding of an induction coil |
| A. | Faradic current |
| B. | Transient ac current |
| C. | Inductive current |
| D. | Capacitive current |
| Answer» B. Transient ac current | |
| 65. |
An ac series circuit is composed of a resistance of 20 a inductive reactance of 40 a and a capacitive reactance of 15 . If a current of 1 ampere is flowinga what is the applied voltage |
| A. | 320 V |
| B. | 32 V |
| C. | 220 V |
| D. | 22 V |
| Answer» C. 220 V | |
| 66. |
What is considered as the most important value of a sine wave? |
| A. | Effective value |
| B. | Peak value |
| C. | Average value |
| D. | Instantaneous value |
| Answer» B. Peak value | |
| 67. |
Which statement is true? |
| A. | A series resonant circuit is of high impedance |
| B. | A parallel resonant circuit is of low impedance |
| C. | A series resonant circuit is inductive if it operates at a frequency higher than the resonant frequency |
| D. | A parallel resonant circuit is inductive if it operates at a frequency higher than the resonant frequency |
| Answer» D. A parallel resonant circuit is inductive if it operates at a frequency higher than the resonant frequency | |
| 68. |
If resonant frequency is 10 kHz and quality factor is 50a then |
| A. | Bandwidth is 200 Hz |
| B. | XL= is 50a000 |
| C. | C R is 50 |
| D. | XC= is 50a000 |
| Answer» B. XL= is 50a000 | |
| 69. |
If a capacitor is rated for 200V dca what is its effective ac working voltage? |
| A. | 50 V |
| B. | 100 V |
| C. | 200 V |
| D. | 400 V |
| Answer» D. 400 V | |
| 70. |
The open-circuit voltage at the terminal of load RL is 60V. Under the condition of maximum power transfera the load voltage will be |
| A. | 60 V |
| B. | 15 V |
| C. | 20 V |
| D. | 30 V |
| Answer» E. | |
| 71. |
Which is considered as the effect of a dielectric material? |
| A. | Increasing capacitance |
| B. | Decreasing capacitance |
| C. | Reducing the working voltage |
| D. | Increasing the distance between the plates |
| Answer» B. Decreasing capacitance | |
| 72. |
As applied to a series RLCcircuita bandwidth means |
| A. | The frequency range for maximum power transfer |
| B. | The difference between the highest and lowest frequencies of the oscillator |
| C. | The separation of the half-power points |
| D. | The frequency at which XL= XC |
| Answer» D. The frequency at which XL= XC | |
| 73. |
What is the temperature coefficient of the resistance Eureka? |
| A. | Infinity |
| B. | Negative |
| C. | Almost zero |
| D. | Positive |
| Answer» D. Positive | |
| 74. |
A capacitive load always has a ______ power facto |
| A. | Leading |
| B. | Lagging |
| C. | Zero |
| D. | Unity |
| Answer» B. Lagging | |
| 75. |
A tank circuit is a |
| A. | Parallel LC circuit |
| B. | Series LCcircuit |
| C. | A resonant circuit |
| D. | A non-resonant circuit |
| Answer» B. Series LCcircuit | |
| 76. |
Kirchhoff�s laws (KCL and KVL) are applicable to |
| A. | DCcircuits |
| B. | ACcircuits |
| C. | DC as well as AC circuits |
| D. | Passive networks alone |
| Answer» D. Passive networks alone | |
| 77. |
A series RLCcircuit has a ______ power factor at its half-power points |
| A. | Unity |
| B. | Leading |
| C. | Lagging |
| D. | Either B or C |
| Answer» E. | |
| 78. |
Two capacitors of capacitance 9 F and 18 F in series will have a total capacitance of |
| A. | 27 F |
| B. | 162 F |
| C. | 6 F |
| D. | 180 F |
| Answer» D. 180 F | |
| 79. |
What is the specific resistance of a pure germanium? |
| A. | 55 -cm |
| B. | 55 -m |
| C. | 55 -mm |
| D. | 55 k -m |
| Answer» B. 55 -m | |
| 80. |
If three 9 mH inductors are connected in parallel without mutual inductance then the total i nductance is |
| A. | 3 mH |
| B. | 9 mH |
| C. | 27mH |
| D. | 18 mH |
| Answer» B. 9 mH | |
| 81. |
In an ac circuit with inductive reactance ?, the |
| A. | Phase angle of the circuit is always 45� |
| B. | Voltage across the inductance must be 90� out o f-phase witht he applied voltage |
| C. | Current through the inductance lags its induced voltage by 90� |
| D. | Current through the inductance and voltage across it are180� outof-phase |
| Answer» D. Current through the inductance and voltage across it are180� outof-phase | |
| 82. |
A gang capacitor is a variable capacitor in which capacitance is varied by changing the |
| A. | Dielectric |
| B. | Number of plates |
| C. | Plate area |
| D. | Distance between plates |
| Answer» D. Distance between plates | |
| 83. |
Which of the following conditions is not true for a series RLCcircuit at resonance? |
| A. | Z = jXL |
| B. | XL= XC |
| C. | The power factor is one |
| D. | D The magnitude of Z is |
| Answer» B. XL= XC | |
| 84. |
In a resonant circuita if Q ? 10 resonant frequency _______ bandwidth. |
| A. | Bisects |
| B. | Exceeds |
| C. | Is less than |
| D. | Is equal to |
| Answer» B. Exceeds | |
| 85. |
Resistor with colored bands in the body |
| A. | Wire-wound resistor |
| B. | Carbon-composition resistor |
| C. | Potentiometer |
| D. | Rheostat |
| Answer» C. Potentiometer | |
| 86. |
In a series RLCcircuit |
| A. | The current lags VLby 90� |
| B. | The current leads VLby 90� |
| C. | XL leads Xcby 90� |
| D. | Z = jXL at resonance |
| Answer» B. The current leads VLby 90� | |
| 87. |
What is the other name of relative permittivity? |
| A. | Dielectric strength |
| B. | Potential gradient |
| C. | Breakdown voltage |
| D. | Specific inductance capacity |
| Answer» E. | |
| 88. |
Property of an electric circuit that dissipates electric energy |
| A. | Reactance |
| B. | Impedance |
| C. | Resistance |
| D. | Conductance |
| Answer» D. Conductance | |
| 89. |
At what frequency will an inductor of 5mH have the same reactance as a capacitor of 0.1 F? |
| A. | 7.12 kHz |
| B. | 7.12 Hz |
| C. | 7.12MHz |
| D. | 7.12 GHz |
| Answer» B. 7.12 Hz | |
| 90. |
VL= VCin a series RLCcircuit when |
| A. | The value of the impedance is minimum |
| B. | The power factor is zero |
| C. | The current leads the total voltage by 90� |
| D. | The total voltage is zero |
| Answer» B. The power factor is zero | |
| 91. |
In liquids and gasesa ionization current results from a flow of |
| A. | Positive or negative ions |
| B. | Free electrons |
| C. | Ions that are lighter in weight than electrons |
| D. | Protons |
| Answer» C. Ions that are lighter in weight than electrons | |
| 92. |
What is the reciprocal of quality factor? |
| A. | Power factor |
| B. | Reactive factor |
| C. | Dissipation factor |
| D. | 1/Q factor |
| Answer» D. 1/Q factor | |
| 93. |
The ratio of W/VA in an ac circuit means |
| A. | Power factor |
| B. | Reactive factor |
| C. | Quality factor |
| D. | Load factor |
| Answer» B. Reactive factor | |
| 94. |
The symbol Q refers to |
| A. | Resonance quotient |
| B. | Quality factor |
| C. | Power quotient |
| D. | Qualification test |
| Answer» C. Power quotient | |
| 95. |
Series resonance occurs when |
| A. | XL= XC |
| B. | XL= R |
| C. | Z = R |
| D. | Both A and C |
| Answer» E. | |
| 96. |
Electron flow assumes charges flow from |
| A. | Negative to positive |
| B. | Negative to negative |
| C. | Positive to negative |
| D. | Positive to positive |
| Answer» B. Negative to negative | |
| 97. |
Conventional flow assumes charges flow from |
| A. | Positive to negative |
| B. | Positive to positive |
| C. | Negative to positive |
| D. | Negative to negative |
| Answer» B. Positive to positive | |
| 98. |
In Rutherford experiment the number of a-particles scattered through an angle 60° is 112 per minute, then the number of αα particles scattered through an angle of 90° per minute by the same nucleus is : |
| A. | 28 per min |
| B. | 112 per min |
| C. | 12.5 per min |
| D. | 7 per min |
| Answer» B. 112 per min | |
| 99. |
Which of the following is incorrect regarding Rutherford's atomic model ? |
| A. | Atom contains nucleus |
| B. | Size of nucleus is very small in comparison to that of atom |
| C. | Nucleus contains about 90% mass of the atom |
| D. | Electrons revolve round the nucleus with uniform speed |
| Answer» D. Electrons revolve round the nucleus with uniform speed | |
| 100. |
The distance of closest approach of an αα-particle fired towards a nucleus with momentum p, is r. What will be the distance of closest approach when the momentum of a-particle is 2p ? |
| A. | 2r |
| B. | 4r |
| C. | r/2 |
| D. | r/4 |
| Answer» E. | |