Question

A student determines the focal length of a device X, by focussing the image of a far off object on the screen positioned as shown in the figure below.
The device X is a:
(1) Convex lens
(2) Concave lens
(3) Convex mirror
(4) Concave mirror

Answer 1

Answer:

A student determines the focal length of a device X, by focussing the image of a far off object on the screen positioned as shown in the figure below.

The device X is a:

(1) Convex lens

(2) Concave lens

(3) Convex mirror

(4) Concave mirror

Answer 2

The device X is a 4) Concave mirror.

• A concave mirror, or converging mirror, has a reflecting surface that is recessed inward.
• The concave mirror forms the image at focus when the object is at infinity.

• The concave mirror forms image on the side of the object itself.
• Concave mirrors reflect light inward to one focal point.