A concave mirror has a focal length of 4cm and an object 2cm tall is placed 9cm away from it. Find the nature, position and size of the image formed.

An object is placed at a distance of 100cm from a converging lens of focal length 40cm.

1. What is the nature of image?
2. What is the position of image?

A convex lens produces an inverted image magnified three times of an object placed at a distance of 15cm from it. Calculate focal length of the lens.

An object is 24cm away from a concave mirror and its image is 16cm from the mirror. Find the focal length and radius of curvature of the mirror, and the magnification of the image.

A student wants to project the image of a candle flame on a screen 48 cm in front of a mirror by keeping the flame at a distance of 12 cm from its pole.

1. Suggest the type of mirror he should use.
2. Find the linear magnification of the image produced.
3. How far is the image from its object?
4. Draw ray diagram to show the image formation in this case.

Draw a ray diagram showing the path of rays of light when it enters with oblique incidence:

1. From air into water;
2. From water into air.

The two rays chosen for the construction of ray diagram is:

Ray 1: When the incident ray is parallel to the principal axis, the reflected ray will pass through the focus of concave mirror or it appears to pass through the focus of convex mirror.
Ray 2: When the incident ray passes through or appears to pass through the centre of curvature, the light, after reflection from the spherical mirror, reflects back along the same path.
The image formed is real, inverted, magnified and is formed beyond the centre of curvature.

State and explain the New Cartesian Sign Convention for spherical lenses.

Draw a diagram to show how a converging lens held close to the eye acts as a magnifying glass. Why is it usual to choose a lens of short focal length for this purpose rather than one of long focal length?

Give two uses of concave mirrors. Explain why you would choose concave mirrors for these uses.

A concave mirror produces three times enlarged virtual image of an object placed at 10cm in front of it. Calculate the radius of curvature of the mirror.