Convex and concave lenses

This task is about how concave and convex lenses work.

Two types of lenses are concave and convex.  

a)
Predict what you think will happen when each lens is held about 5cm above a pencil as illustrated in the diagram below.
 
Prediction:  
 
Convex lens:
 
 
 
 
Concave lens:
 
 
 
 
 

 

      

b)
Now collect the lenses and try this out. Draw your results on the diagrams above.
 
c)
In terms of light rays, explain what happens for each lens.
 
  Convex lens:
 
 
 
 
  Concave lens:
 
 
 
 
 
d)
Name or describe a practical situation where each lens could be used.
 
  Convex lens:
 
 
  Concave lens: