C&G lighting units and inverse square

What is the flow of light emitted from a light source measured in?

• Lumens

• Lux

• Candela

• Luminous Intensity

What is the measure of light falling on a surface?

• Lux

• Lumens

• Luminous Intensity

• Candela

What is the illuminating power of light in a given direction measured in?

• Candela

• Lux

• Luminous Intensity

• Lumens

Where are lux levels measured?

• At the light source

• On the ceiling

• At the working plane

• On the walls

What is the recommended illuminance level for a school art room?

• 150 Lux

• 500 Lux

• 1000 Lux

• 300 Lux

What is the mean level of illuminance throughout the life of the lighting system averaged over the area illuminated called?

• Illuminance

• Luminous Intensity

• Luminous Flux

• Mean Illuminance

What law describes the dissipation of light over a larger area as the distance from the point source of light increases?

• Inverse Cube Law

• Cube Law

• Square Law

• Inverse Square Law

A light fitting has a Luminous Intensity of 3200cd and is 3.8 metres above a surface. Calculate the Illuminance (lux) at the surface (2 significant figures)

• 220 Lux

• 880 Lux

• 660 Lux

• 440 Lux