P14.4 Lenses

Question 1

What is a convex lens? (Converging lens)

Answer 1

Makes parallel rays converge to a focus

Question 2

What is the principal focus?

Answer 2

The point where parallel rays are focused to

Question 3

What is a converging lens used for?

Answer 3

As a magnifying glass and in a camera to form a clear image of a distant object

Question 4

What is a concave lens? (Diverging lens)

Answer 4

Makes parallel rays diverge

Question 5

What is a diverging lens used for ?

Answer 5

To correct short sight

Question 6

What is the focal length?

Answer 6

The distance from the centre of the lens to the principle focus

Question 7

How is a magnified image produced?

Answer 7

When the object is nearer to the lens than the principal focus

Question 8

What is the magnification formula?

Answer 8

Magnification = image height/object height

Question 9

When is a real image formed by a convex lens?

Answer 9

If the object is further away than the principal focus

Question 10

When is a virtual image formed by a convex lens?

Answer 10

If the object is nearer than the principal focus