136. Wavelength for blue color
(A) 4400 A
(B) 5250 A
(C) 6150 A
(D) 5950 A
137. Radio interference from a fluorescent lamp can be reduced by
(A) putting two lamps in parallel
(B) eliminating choke
(C) putting a capacitor across the lamp
(D) none of the above
138. Dimming systems for lights are used in
(A) theatres
(B) auditoriums
(C) ball room
(D) all of the above
139. Which of the following can be used as a light dimming device?
(A) Auto transformer
(B) Variable reaction
(C) SCR
(D) Any of the above
140. Which of the following is difficult to adopt for dimming?
(A) GLS lamps
(B) Cold cathode lamps
(C) Fluorescent lamps
(D) All of the above.
141. Heat from light source is particularly of importance while
(A) designing for illumination level
(B) designing for floor space utilization
(C) designing for air conditioning
(D) all of the above.
142. In electric discharge lamps for stablizing the arc
(A) a condenser is connected in parallel to supply
(B) a condenser is connected in series to supply
(C) a variable resistor is connected in the circuit
(D) a reactive choke is connected in series with supply.
143. The lens of the eye to focuses an image on the
(A) corona
(B) membrane
(C) calorie
(D) retina
144. The sensors in the eye are known as
(A) rods and cones
(B) wires and nerves
(C) retina and antenna
(D) high and low
