QUIZ - 5



  1. For 1 cm gap in air at 760 mm pressure and 200C temperature the Break Down Voltage is -
      2. 14 kV
      30.3 kV
      22.92 kV
      40 kV


  2. Sphere gaps are used to measure -
      3. DC Voltages
      AC Voltages
      DC, AC peak and impulse voltages
      Only DC and AC peak voltage


  3. Sphere gap BDV measurement is linear and valid for gap spacing less than -
      4. the Radius of sphere
      the diameter of sphere
      Half the radius of sphere
      Two times the diameter of sphere


  4. In volt-time characteristics, the breakdown voltage for a negative impulse is _______the positive impulse.
      5. Less Than
      Greater Than
      Equal To
      None of these


  5. The main factors that affect the spark over voltage of sphere gap are -
      6. Humidity and waveform
      Nearby earthed objects and atmospheric conditions
      Diameter of sphere
      Gap spacing, diameter & waveform


  6. Impulse ratio of a rod gap -
      7. Unity
      Between 1.2 and 1.5
      Between 1.6 and 1.8
      Between 2 and 2.2


  7. which electrode has minimum breakdown voltage -
      8. Sphere electrode
      Pointed electrode
      Flat Electrode
      Big sphere electrode


  8. The insulation of the modern EHV lines is designed based on -
      9. The lightning voltage
      The switching voltage
      Corona
      RI


  9. Minimum sparking potential of Air is about -
      10. 100 V
      4.4 kV
      40 V
      325 V


  10. Electrostatic voltmeter can measure -
      11. Only DC voltages
      Both DC and AC voltages upto high frequency
      Impulse voltages
      Only DC and AC peak voltages