Optical Instruments Physics - Optical Instruments

A person A can clearly see objects between 25cm and 200cm. Which of the following may represent the range of clear vision for a person B having muscles stronger than A, but all other parameters of eye identical to that of A?

1. 25cm to 200cm.
2. 18cm to 200cm.
3. 25cm to 300cm.
4. 18cm to 300cm.

The muscles of a normal eye are least strained when the eye is focused on an object:

1. Far away from the eye.
2. Very close to the eye.
3. At about 25cm from the eye.
4. At about 1m from the eye.

When objects at different distances are seen by the eye, which of the following remain constant?

1. The focal length of the eye-lens.
2. The object-distance from the eye-lens.
3. The radii of curvature of the eye-lens.
4. The image-distance from the eye-lens.

A man wearing glasses of focal length +1m cannot clearly see beyond 1m:

1. If he is farsighted.
2. If he is nearsighted.
3. If his vision is normal.
4. In each of these cases.

 A man is looking at a small object placed at his near point. Without altering the position of his eye or the object, he puts a simple microscope of magnifying power 5X before his eyes. The angular magnification achieved is:

1. 5
2. 2.5
3. 1
4. 0.2

Can the image formed by a simple microscope be projected on a screen without using any additional lens or mirror?

A person is viewing an extended object. If a converging lens is placed in front of his eyes, will he feel that the size has increased?

A person wears glasses of power -2.5D. Is the person farsighted or nearsighted? What is the far point of the person without the glasses?

A person wears glasses of power -2.5D. Is the person farsighted or nearsighted? What is the far point of the person without the glasses?

The angular magnification of a system is less than one. Does it mean that the image formed is inverted?

A simple microscope is rated 5 for a normal relaxed eye. What will be its magnifying power for a relaxed farsighted eye whose near point is 40cm?

A simple microscope has a magnifying power of 3.0 when the image is formed at the near point (25cm) of a normal eye.

1. What is its focal length?
2. What will be its magnifying power if the image is formed at infinity?

A person looks at different trees in an open space with the following details. Arrange the trees in decreasing order of their apparent sizes.

Tree	Height(m)	Distance form the eye(m)
A	2.8	50
B	2.5	80
C	1.8	70
D	2.8	100

A magnifying glass is a converging lens placed close to the eye. A farsighted person uses spectacles having converging lenses. Compare the functions of a converging lens used as a magnifying glass and as spectacles.

A lady cannot see objects closer than 40cm from the left eye and closer than 100cm from the right eye. While on a mountaineering trip, she is lost from her team. She tries to make an astronomical telscope from her reading glasses to look for her teammates.

1. Which glass should she use as the eyepiece?
2. What magnification can she get with relaxed eye?

A child has near point at 10cm. What is the maximum angular magnification the child can have with a convex lens of focal length 10cm?

By mistake, an eye surgeon puts a concave lens in place of the lens in the eye after a cataract operation. Will the patient be able to see clearly any object placed at any distance?

An object is placed at a distance of 30cm from a converging lens of focal length 15cm. A normal eye (near point 25cm, far point infinity) is placed close to the lens on the other side.

1.  Can the eye see the object clearly?
2.  What should be the minimum separation between the lens and the eye so that the eye can clearly see the object?
3.  Can a diverging lens, placed in contact with the converging lens, help in seeing the object clearly when the eye is close to the lens?