Illumination Quiz

What is the rate of emission of light from a light source?

• Glow of light

• Luminous flux

• Illuminance

• Luminous intensity

What is the luminous flux falling on unit surface area?

• Glow of light

• Luminous flux

• Illuminance

• Luminous intensity

Which is the correct formula for point-source illuminance?

• E= P/4πr2

• E= 4P πr2

• E= P/4πr

• E= 4P πr

Which best describes the relationship between distance and illuminance?

• E∝r

• E ∝1/r

• Eα1/r2

• E∝r2

If distance between the object and the light source is doubled,the luminous flux,P

• Remain the same

• decrease by factor of 2

• decrease by factor of 4

• increase by factor of 2

If distance between the object and the light source is doubled,the illuminance,E

• Remain the same

• decrease by factor of 2

• decrease by factor of 4

• increase by factor of 2

Unit of luminous intensity

• Candela

• Lux

• Lumen

What is the unit of luminous flux?

• Lumen

• Candela

• Lux

What is the unit of Illuminance,E?

• Candela

• Lumen

• Lm/m^2