Exam 25: Optical Instruments

A $35 - \mathrm { mm }$ camera equipped with a $40 - \mathrm { mm }$ focal length lens is used to photograph a tree $17 \mathrm {~m}$ tall. If a 32-mm high image of the tree on the CCD sensor is required, how far should the camera lens be from the tree?

Which one of the following statements is correct?

A nearsighted person has a far point that is 4.2 m from his eyes. What power contact lenses must he wear to allow him to focus on distant mountains?

If a camera lens aperture is set to $f / 4$ , then

A person's near point is 25 cm, and her eye lens is 2.7 cm away from the retina. What must be the focal length of this lens for an object at the near point of the eye to focus on the retina?

What is the maximum possible angular magnification of the converging lens of focal length 5 cm for a person with normal vision?

The focal length of the objective lens of a telescope is 0.20 m and the eyepiece has a focal length of 1.6 m. What is the length of this telescope?

The angular magnification of a refracting telescope is 40. When the object and final image are both at infinity, the distance between the eyepiece and the objective is 143.5 cm. The telescope is used to View a distant radio tower. The real image of the tower, formed by the objective, is 6.0 mm in Height. The focal point of the eyepiece is positioned at the real image. What is the focal length of The objective lens?

A magnifying glass has a focal length of $7.0 \mathrm {~cm}$ . What is the angular magnification if the image is viewed by a person having a relaxed eye with the near point of $25 \mathrm {~cm}$ ?

Jack and Mary view the same microorganism through the same compound microscope. Mary's near point distance, NM, is twice as large as Jack's near point distance, NJ. If Mary sees the Microorganism with magnification MM, with what magnification does Jack see it?

Cal is viewing the Moon with his new telescope, using a 10-mm focal length eyepiece. For greater detail, he wishes to double the magnification of his telescope. An eyepiece having which one of the Following characteristics will accomplish this for him?

A machinist with normal vision has a near point at 25 cm. This machinist wears +4.25-diopter eyeglasses in order to do very close work. With these eyeglasses, what is the near point of the Machinist? Assume that he wears the glasses extremely close to his eyes.

The closest object that a typical young person with normal vision can focus on clearly is closest to

The two stars in a binary star system have an angular separation of $1.0 \times 10 ^ { - 5 } \mathrm { rad }$ . If the wavelength of the light from the system is $500 \mathrm {~nm}$ , what is the smallest diameter aperture telescope that could just resolve this system to show that it contains two stars?

A nearsighted person has a far point of 18 cm. What power contact lenses will allow this person to comfortably see distant objects clearly?

What power (in diopters) of corrective contact lens is required to correct the vision of a myopic eye whose far point is at 170 cm?

You have a choice between two lenses of focal lengths fa and fb, where fb = 2fa, to use as the objective lens in building a compound microscope. If the magnification you obtain using lens a is Ma, what will be the magnification when using lens b?

If the lens in a person's eye is too highly curved, this person is suffering from

In one particular case, the limiting angle of resolution for an eye is $1.4 \times 10 ^ { - 4 } \mathrm { rad }$ . What is the minimum separation between two point sources of light that the eye can distinguish if they are at a distance of $40 \mathrm {~m}$ from the observer?

A person is designing a telescope with a magnification of 10. If the telescope is limited to a length of 0.20 m, what is the approximate focal length of the objective?