Light travels in a _________ path.

• circular

• straight

• curved

In order to see an object, the object must ______.

• reflect light towards your eyes

• send (emit or reflect) light towards your eyes

• absorb light

• transmit light

We cannot change the direction of light.

• True

• False

What is the definition of the ray model of light?

• Light travels in a straight path and its direction can be changed by encountering a boundary.

• Objects that emit their own light.

• The rate at which a luminous source produces light energy.

• The rate at which light strikes a unit area of a surface.

Objects that can be seen due to light reflecting from them are called

• Luminous flux

• Luminous sources

• Illumminate sources

• Power sources

Objects that absorb and reflect light but do not transmit it are

• transparent

• translucent

• opaque

• luminous

All three types of objects (transparent, translucent and opaque) absorb some light.

• True

• False

We can see through a surface only if it

• transmits light

• absorbs light

• reflects light

What is the definition of luminous flux?

• Light travels in a straight path and its direction can be changed by encountering a boundary

• Objects that emit their own light

• The rate at which a luminous source produces light energy

• The rate at which light strikes a unit area of a surface

The units for luminous flux, illuminance and luminous intensity, respectively, are

• lumen, candela and lux

• lux, candela and lumen

• candela, lux and lumen

• lumen, lux and candela