A) 20% B) 40% C) 60% D) 80%. Ans : (A)
A) Helium B) Mercury C) Sodium D) Magnesium. Ans : (C)
A) Calcium halo phosphate B) Magnesium tungstate C) Cadmium borate D) Zinc silicate. Ans : (D)
A) rate of energy radiation in the form of light waves B) light energy radiated by sun C) part of light energy, radiated by sun which is received on earth D) none of the above. Ans : (A)
A) candle power of the source B) distance of the source C) type of reflector used D) ambient temperature. Ans : (D)
A) 25 lumens B) 25 lumens C) 314 lumens D) 625 lumens. Ans : (C)
A) tantalum B) tungsten C) carbon D) any of the above. Ans : (D)
A) when supply frequency is low B) to reduce radio interference C) when tube operates on dc supply D) to reduce stroboscopic effects. Ans : (C)
A) Longer life B) Less costly C) More brightness D) Simple installation. Ans : (A)
A) 1800o C B) 2200o C C) 3500o C D) 5500o C. Ans : (C)