what is the frequency of electromagnetic radiation and its wavelength

1.The frequency of electromagnetic radiation and its wavelength are

 

(a) of no interest to the lighting designer

(b) proportional to one another

(c) the same thing

(d) inversely proportional

2. The visible part of the electromagnetic spectrum

(a) lies between the infra-red and the ultraviolet sections

(b) is the green part of the spectrum

(c) cannot be seen by the human eye

(d) is at a wavelength of 700 nm

3.The illuminance of a surface is measured in units which are called

(a) lumens (b) lux (c) candle power (d) candelas

4. A 2000 cd lamp is hung above a level surface, which has an illuminance of

125 lx directly below the lamp. The distance from the lamp to the surface is

(a) 16 m (b) 6.25 m (c) 4 m (d) 4 cm

5. If the surface of Example 12M5 were tilted through 25° the illumination of the surface directly below the lamp would become

(a) 113 lux (b) 22 lux (c) 53 lux (d) 138 lux 1

6. Four 1000 cd lamps are mounted 4 m apart on 3 m high poles in a straight line above a level surface. The lighting level on the surface directly beneath the second lamp in the line will be

(a) 111 lux (b) 161 lux (c) 24 lux (d) 1.6 lux

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