Photometrics Level 2 Quiz

1.- Candela is the unit for which of the following photometric quantities?

2.- An optical source of luminous flux of 5 lumens shines its light in a cone of 2 sr. The cone intersects a 10m² area on a wall nearby. What is the luminous intensity of the source and the illuminance on the wall respectively?

3.- What is the radiance and luminance of a source of light if it subtends a 0.2 sr solid angle, has 2 watts of power emitting from a 0.01 m² area and its wavelength is 555 nm? PS: One watt of light at 555 nm corresponds to 683 lumens.

4.- A cone of light subtends a circular area of radius 1 m on a nearby screen located at a 10 m distance. What is the solid angle of this cone?

5.- If the first two CIE chromaticity coordinates are given by x=0.2 and y=0.6, what is the value of the third chromaticity coordinate z?

6.- Referring to the following CIE 1931 chromaticity diagram, where E is the reference source and F is the test source, what is the most likely DOMINANT WAVELENGTH for the test source? (Please refer to diagram 6)

7.- Two sources A and B ( represented by black circles) lie on the opposite sides of the Planckian locus as shown in the figure. Which statement is correct about these two sources? (Please refer to diagram 7)

8.- Which of the following sources does not have a CCT? (Please refer to diagrams 8.a, 8.b, 8.c and 8.d)

9.- Which of the following steps is not necessary in the procedure to calculate the average CRI?

10.- An automobile headlamp (high beam) is most likely to have which iof the following candela levels?


11.- Purity as defined by CIE 1931 x, y chromaticity coordinates is defined as Pe=(Yf-Y0)/(Yd-Y0 )= (Xf-X0)/(Xd-X0 ) Where the suffix 0 indicates the white reference point, F is the test source and d is the dominant wavelength. Based on this definition, which of the following test sources, F1 and F2 have a higher purity? (Please refer to diagram 11)

12.- In the following 1960 chromaticity diagram, what is the most likely Duv of the source F? (Please refer to diagram 12)

13.- By referring to the following diagram, indicate which of the following statements is NOT correct? (Please refer to diagram 13)

14.- Two light bulbs have exactly the same CRI index of 70 as shown in the figure but produce different rendering of blue color (The blue in the left picture is more pronounced). What is the most UNLIKELY reason for this effect? (Please refer to diagram 14)

15.- What are the limitations of CRI?

16.- What is the most likely flicker frequency for a fluorescent light?

17.- What are the advantages of IES-TN-30-15?

18.- What do the arrows in the following graphical representation show in TM-30-15 standard? (Please refer to diagram 18)

19.- Which vector graph most likely corresponds to the above TM30-15 Rg-Rf graph? (Please refer to diagrams 19.a, 19.b, 19.c and 19.d)

20.- Which source has more saturated colors according to this Tm_30-15 diagram? (Please refer to diagram 20)