Sodium Vapour Lamp Multiple Choice Questions and Answers

21.  The sodium vapour lamp

   A. Is only suitable for AC and so needs choke control

   B. Needs capacitor in its autotransformer circuit to improve the power factor which is very low

   C. Comes up to its rated output in approximately 15 minutes

   D. All of the above

22.  In sodium vapour discharge lamp the neon gas

   A. Changes the colour of light

   B. Prevents vaporisation of filament

   C. Acts as a shield around the filament

   D. Assists in developing enough heat to vaporised the sodium

23.  The capacitor is used in auto transformer circuit of a sodium vapour lamp in order to

   A. Regulate discharge voltage

   B. Improve the circuit power factor

   C. Control lamp illumination level

   D. Protect the lamp against overvoltage

24.  An auto transformer used with a sodium vapour lamp should have

   A. High step up ratio

   B. High step down ratio

   C. High leakage reactance

   D. High resistance

   E.None of the above

25.  Leak transformer is a sodium vapour lamp initially provides

   A. High current

   B. Low voltage

   C. High voltage

   D. Low current

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