Revision Geometrical Optics

A concave lens forms the image of an object such that the distance between the object and image is 10 cm and the magnification produced is 1/4. The focal length of the lens will be : __________

• 8.6 cm

• 6.2 cm

• 10 cm

• 4.4 cm

If the distances of an object and its virtual image from the focus of a convex lens of focal length f are 1 cm each, then f is _______________

• 4 cm

• (√2 +1) cm

• 2√2 cm

• ( 2 + √2 ) cm

To determine the characteristics of image formed we need to a draw ray diagram that uses

• at least 2 rays that overlap each other

• at least 3 rays out of 4 rays

• plane mirror or lens

• rays that passes through biconcave or biconvex mirror

An image is formed upside down in front of mirror and seems bigger by 2 times from the actual size. What might be the type of mirror uses?

• concave mirror

• convex mirror

• plane mirror

• concave lens

An object is placed 20 cm at the left side of a biconcave lens with focal length of 12 cm. Find the position of the image formed.

• -7.5 cm

• 30 cm

• -30 cm

• 7.5 cm

Calculate the focal length when given u=15cm and a virtual image at 25 cm is formed. State the type of lens used.

• 37.5 cm (biconcave lens)

• -37.5 cm (biconcave lens)

• 37.5 cm (biconvex lens)

• 9.4 cm (biconvex lens)

What is the characteristic of image formed when given that u and f have the same value of length

• real or virtual, image formed at infinity

• same size, inverted and real

• magnified, inverted and real

• magnified, upright and virtual

Which terms describe the reflection seen in this image?

• virtual, upright
• virtual, inverted
• real, upright
• real, inverted

Tags

NGSS.MS-PS4-2

The point in the middle way between a curved mirror and the center of curvature is the

• principle point
• focal point
• center of curvature
• principle axis

Concave lenses, like the ones found in the peepholes of a door, always produce images that are .....

• Virtual, upright, smaller
• Real, inverted, larger
• Real, inverted, smaller
• Virtual, upright, larger