Exam 27: Optical Instruments

The distance between the object and the eyepiece of a compound microscope is 25 cm. The focal length of its objective lens is 0.20 cm and the eyepiece has a focal length of 2.6 cm. A person with a near point 25 cm is using the microscope. What is the largest angular magnification obtainable using the eyepiece alone as a magnifying lens?

The focal lengths of the objective and eyepiece in a compound microscope are 0.8 cm and 2.5 cm, respectively. The image formed by the objective is 16 cm from it and the final image is 25 cm from the eye. What is the total magnification?

Farsightedness can be corrected with a converging lens.

The length of a telescope is 2.20 m and the focal length of the eyepiece is 1.9 cm. What is the focal length of the objective?

What type of lens is a magnifying glass?

What is the near point of a farsighted person who can read a newspaper held 25 cm from his eyes when he wears 3.33 diopters glasses?

Jill is farsighted and cannot see objects clearly that are closer to the eye than 80.0 cm. What is the focal length of the contact lenses that will enable her to see objects at a distance of 25.0 cm from her eyes?

Nearsightedness can usually be corrected with

In a nearsighted person the eye makes the light coming into it converge too rapidly.

The focal length of the objective of a telescope is much longer than the focal length of the eyepiece.

The focal length of the lens of a simple camera is 40 mm. In what direction must the lens be moved to change the focus of the camera from a person 25 m away to a person 4.0 m away?

A magnifying glass can be made from a diverging lens.

Which one of the following is not a characteristic of a simple two-lens astronomical refracting telescope?

Which one of the following is a characteristic of a compound microscope?

You are given two converging lenses to build a compound microscope. Lens A has focal length 0.50 cm and lens B has focal length of 3.0 cm. Which of the two lenses would you use for the objective?

A simple refracting telescope provides large magnification by employing

The focal length of a magnifying glass is 15 cm. If the near point of a person is 25 cm, what is the magnification of this glass for this person when his eyes are focused at infinity?

John is nearsighted and cannot see things beyond 110 cm from his eyes. What is the focal length of the contact lenses that will enable him to see distant objects clearly?

A person's eye lens is 2.7 cm away from the retina. What must the focal length of this lens be in order for an object placed at the near point (N = 25.0 cm) of the eye to focus on the retina?

The focal lengths of the objective and the eyepiece in a microscope are 0.29 cm and 2.50 cm, respectively. An object is placed at 0.30 cm from the objective lens and the image of this object is viewed with the eyepiece adjusted for minimum eyestrain. The near-point distance of the person using the microscope is 25.0 cm. What is the final magnification of the microscope?