8k: Light

the iris in your eye
1. changes the size of the pupil
2. focusses the light
3. forms an image
4. passes the image to the optic nerve
the cornea in your eye
1. does most of the focussing
2. changes the size of the pupil
3. passes the image to the optic nerve
4. focusses the light
the retina in your eye
1. passes the image to the optic nerve
2. changes the size of the pupil
3. focusses the light
4. changes size to cope with different light levels
the lens in your eye
1. changes shape to focus the light from near or far objects
2. passes the image to the optic nerve
3. changes the size of the pupil
4. changes size to cope with different light levels
Light travels in straight lines. This explains why
1. we get shadows
2. your pupil needs to be able to change size
3. filters can change the colour of light
4. we have two eyes
we have two eyes
1. to help us judge distances
2. to help us see in low light levels
3. to help us see more clearly
4. none of these reasons
light travels faster than sound. This explains
1. why we see lightning before we hear thunder
2. why we hear thunder before we see lightning
3. how shadows are formed
4. how lenses focus light
"angle of incidence = angle of reflection" This is called
1. Snell's Law of reflection
2. Newton's 2nd Law
3. Snell's Law of refraction
4. Boyle's Law
When measuring angles with light rays and mirrors, we draw an imaginary line called the
1. normal
2. perpendicular
3. horizontal
4. incidence
a plane mirror is
1. a flat mirror
2. used in fighter aircraft cockpits
3. a magnifying mirror
4. a torch reflector
white surfaces
1. reflect all the light that hits them
2. absorb most of the light that hits them
3. reflect selected wavelengths of visible light
4. none of these
black surfaces
1. absorb most of the light that hits them
2. reflect all the light that hits them
3. reflect selected wavelengths of visible light
4. none of these
convex mirrors are used
1. in shops, for security
2. in torches
3. in make-up mirrors
4. in car headlamps
concave mirrors are used
1. in torches
2. in shops, for security
3. to give a wide-angle view
4. none of these
The distance from an object to a plane mirror is _______ to the distance from the ______ to the mirror
1. equal, image
2. image, equal
3. greater than, image
4. equal, object
you can see over tall obstructions using a
1. periscope
2. microscope
3. epidiascope
4. stethoscope
refraction is
1. light changing direction when it enters or leaves glass
2. light bouncing off a surface
3. white light being split into colours
4. when light is absorbed by a surface
convex lenses make light rays
1. converge
2. diverge
3. spread apart
4. reflect
concave lenses make light rays
1. diverge
2. converge
3. get closer together
4. reflect
convex mirrors make light rays
1. diverge
2. converge
3. get closer together
4. refract
when you look at a distant object, the lens in your eye is
1. thinner, to bend the rays less
2. fatter, to bend the rays more
3. concave, to make the rays diverge
4. larger, to let more light through
when you look at a nearby object, the lens in your eye is
1. fatter, to bend the rays more
2. thinner, to bend the rays less
3. concave, to make the rays diverge
4. larger, to let more light through
the image on your retina is
1. inverted (upside down)
2. erect (the right way up)
3. virtual
4. formed by the ciliary muscles
the retina in your eye is like
1. the film in a camera
2. the shutter in a camera
3. the lens in a camera
4. the reflector in a spotlight
a red surface
1. only reflects red light, and absorbs the other colours
2. reflects all colours
3. absorbs red light, and reflects all the other colours
4. absorbs all colours
white light
1. is a mixture of all the colours
2. cannot be split into component colours
3. is made of six clearly-defined colours
4. is a mixture of red, blue and yellow
a red filter
1. only passes red light, and absorbs all the other colours
2. passes all colours
3. absorbs red light, and passes all the other colours
4. reflects all colours
the primary colours for light are
1. red, green, blue
2. red, blue, yellow
3. green, blue, yellow
4. red, yellow, blue
the primary colours for paints are
1. red, blue, yellow
2. red, green, blue
3. red, yellow, green
4. blue, yellow, green
road signs and safety jackets need to reflect light back the way it came. We call them
1. retroreflective
2. translucent
3. convex
4. focussed
My car wing mirror says "objects are closer than they appear". It must be a
1. convex mirror
2. concave mirror
3. plane mirror
4. magnifying mirror