If the focal length of a concave lens is 6 cm, the radius of curvature equals

• 3

• 6

• 9

• 12

A convex lens, the distance between its focus and its optical center is 10 cm,

so the double of the focal length is

• 10

• 20

• 30

• 40

If the radius of curvature of a lens is 40 cm, its focal length equals :

• 10

• 20

• 30

• 40

Lenses used in the:

• cameras.

• medical glasses

• binoculars.

• all answers

Tags

NGSS.HS-PS4-3

NGSS.HS-PS4-5

Concave lens is called:

• diverging

• converging

• collecting

• converging and collecting

The straight line that joins between the two centers of curvature of the lens and passes

through its its optical center is called

• the focal length.

• the principal axis.

• the secondary axis.

• the radius of curvature.

A concave mirror of focal length 10 cm, to form an equal image to a body, the body should be placed at ----------from the mirror

• 20

• 30

• 15

• 10

Light rays coming from the Sun are________:

• convergent

• parallel

• re elected

• divergent.

Tags

NGSS.HS-PS4-3

a light ray falls parallel to the principal axis of a concave mirror will reflects ___________

• passing by the spherical center of the mirror.

• passing by the focus.

• on itself.

• passing by the optical centre,

When the object is very far from a concave mirror.

image is formed_________

• magnified

• real

• very tiny

• real and very tiny