2. (a) In an office, a light source of 400 cd is placed above a 0.6...

 

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2. (a) In an office, a light source of 400 cd is placed above a 0.6 m office table. Assuming that the light source is at a height of 3 m vertically from the floor and the height of the office table is 0.8 m. Find (i) the value of illuminance, E, on the top of the office table; (5 marks) (ii) the luminous flux, F, falls on the top the office table. (5 marks) (b) A 60 cd spotlight is located at 2.0 m above a table. The beam is focused on a surface area of 0.6 m. Find the intensity of the beam. (5 marks) (c) Explain with the aid of a diagram, the laws of reflection. (5 marks) 2. (a) In an office, a light source of 400 cd is placed above a 0.6 m office table. Assuming that the light source is at a height of 3 m vertically from the floor and the height of the office table is 0.8 m. Find (i) the value of illuminance, E, on the top of the office table; (5 marks) (ii) the luminous flux, F, falls on the top the office table. (5 marks) (b) A 60 cd spotlight is located at 2.0 m above a table. The beam is focused on a surface area of 0.6 m. Find the intensity of the beam. (5 marks) (c) Explain with the aid of a diagram, the laws of reflection. (5 marks)