Electric Illumination: True-False Questions

Q. Carbon arc lamps need frequent adjustment and replacement of carbon rod.

Answer
True

Q. Lumen method takes into account the inter-reflections of light inside a room.

Answer
True

Q. Luminaires are generally categorized as industrial, commercial or residential.

Answer
True

Q. Lenses with prismatic patterns refract light sources to disperse the rays or to direct them most effectively.

Answer
True

Q. High-pressure sodium vapour Lamps use metallic sodium sealed in translucent aluminium oxide tubes.

Answer
True

Q. A standard candle is also known as meter candle.

Answer
True

Q. Incandescent-lamp filaments are generally constructed of copper.

Answer
False

Q. Candelabra refers to the base of an incandescent lamp.

Answer
True

Q. The luminous efficacy is expressed in lumen output per radiated watt.

Answer
True

Q. Lumen is the unit of luminous flux.

Answer
True

Q. Illuminance is the density of luminous flux on a surface.

Answer
True

Q. A source of one candela emits a total of one lumen.

Answer
False

Q. Glare is the condition of comfort produced by an object of luminance.

Answer
False

Q. Incandescent lamps should always be used without luminaries.

Answer
False

Q. The diameter of tungsten filament for GLS lamps is in terms of microns.

Answer
True

Q. Halogen lamps are preferred for indoor illumination.

Answer
True

Q. A starter in a fluorescent tube is used for preheating the electrodes.

Answer
True

Q. Starter use for a fluorescent tube is a generally glowing type.

Answer
True

Q. After about 4000 hours of use, the light output of a fluorescent tube is reduced by 15 to 20%.

Answer
True

Q. Sodium vapour lamp is also known as a cold-cathode low-pressure lamp.

Answer
True

Q. With the use of a fluorescent tube, walls blacken little and dark rings appear near the ends due to the deposition of active material from the electrodes.

Answer
True

Q. Fluorescent tubes operating on dc are generally free from stroboscopic effect.

Answer
True

Q. A ‘leak transformer’, provided on sodium lamps acts as a step-down transformer initially.

Answer
False

Q. The average life of sodium lamps is estimated at 6000 hrs.

Answer
True

Q. Mercury iodide lamps are used for flood lighting.

Answer
True

 

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