Check Test 2 - Optics
1 Which two devices often form real images of real objects?
A convex lens (magnifying glass) and a concave mirror.
b A convex lens (magnifying glass) and a plane mirror.
2 Which rays (marked A, B, C and D) will eventually pass through the focal point of the eyepiece?
A, B, C and D
3 Which statement is correct .....
Only two rays are required to predict the image position on the ray diagram for a magnifying glass.
4 A student sees two images of a ceiling light when he looks for the reflections in a lens. An image which is below the lens must be ....
... virtual.
5 A partial ray diagram is shown for a magnifying glass.
To view the image the eye must be placed at ...
... D.
6 Following the normal sign convention, the focal lengths of which two devices are both negative?
A convex mirror and a concave lens.
7 A real image of a real object formed by a single convex lens is always ....
... inverted.
8 Which of the following telescopes, of the same diameter and magnification, has the smallest field of view?
Galilean.
9 A refracting telescope is two meters long. The focal length of the eyepiece is 2 cm.
The magnification of the telescope is approximately ....
... x 100
10 Which of the following statements is correct?
A refracting telescope can be made with just one large curved glass surface.
11 You have four lenses as shown.
Which would be the best selection with which to make a Galilean telescope?
.... C as objective and B as eyepiece.
12 A simple microscope is made from two lenses. The object is placed at D.
The focal length of the eyepiece (not shown) would normally be ....
Longer than that of the objective.
13 The final image in a microscope is sometimes formed at the near point of the eye because......
... the magnification is then increased to a maximum.
14 A microscope has an objective with a magnification of x10, and an eyepiece with a magnification of x5.
The magnification of the microscope is ...
... x50.
15 The problem that requires cable operators to insert repeater stations every ten kilometers or less on under-sea optical cables is best described as....
... dispersion
16 The plastic sheath on the outside of a glass optical fiber is put there to prevent signals leaking between fibers.
The plastic has ...
..... a slightly lower refractive index.
17 Signal transmission on optical fibers is done with ....
.... infrared laser light.
18 Colored fringes around bright objects seen in a microscope are less of problem if .....
..... a lens stop is inserted to reduce the effective area of the lenses.
19 The problems caused by spherical aberration in the Hubble Space Telescope were corrected by ....
.... introducing correcting optics and a new camera.
20 A student is making a demonstration microscope on a bench. He has two lenses and a filament bulb.
Which of the following would not be helpful.
Using a dimmer on the light.
21 Two lenses are selected with powers of +2 and -5.
The focal lengths of the lenses are ..... (respectively).
..... 50 cm and - 20 cm
22 The wavelength of green light may be taken as approximately ....
..... 500 nm.
23 The image of a star in a telescope is .....
..... a diffraction pattern.
24 The images of two stars in a telescope are just resolved by Rayleigh's criterion if ...
.... the images can be described as two overlapping circular ripple patterns.
25 A student is not able to resolve two distant yellow car headlights at night.
Which of the following statements is correct.
He would be more likely to resolve the headlights if they were closer.