PARTICIPACION DE LOS PRINCIPALES DEPOSITOS EN EL PIB A PRECIOS CORRIENTE
4.1 EVOLUCIÓN MACROECONÓMICA SECTOR VIVIENDA
(C)
n
violetn
red (D) This depends on the relativ e speeds of the different colors in a vacuum. 54. Total internal reflection first occurs when a beam of light travels from one medium to another medium which has a smaller refractive index at such an angle of incidence that the angle of refraction is 90°. This angle of incidence is called the critical angle. What is the value of the sine of this angle when the ray moves from water towards air?(A) 2 (B) 0.75 (C) 0.50 (D) 0
55. What would happen to the critical angle, in the previous question, if the beam of light was travelling from water to a substance with a greater refractive index than air, but a lower refractive index than water?
(A) It would increase (B) It would decrease
(C) It would remain the same (D) Total internal reflection would not be possible.
56. Which of the following would you expect to remain constant when light travels from one medium to another and the media differ in their refractiv e indices?
(A) Velocity (B) Frequency (C) Wavelength (D) Intensity. THE NEXT QUESTIONS REFER TO THE FOLLOWING PASSAGE
The invention of the compound microscope by Jansen in the late 1500’s truly revolutionized the world of science, particularly the field of cellular and molecular biology. The discovery of the cell as the fundamental unit of living organisms and the insight into the bacterial world are two of the contributions of this instrument to science.
It is unseemly that such a relatively simplistic apparantus took generations to be developed. Its main component are two convex lenses: one acts as the main magnifying lens and is referred to as the objective, and another lens called the eyepiece. The two lenses act independently of each other when bending light rays. The actual lens set-up depicted in Figure.
Light from the object (O) first passes thought he objective and an enlarged, inverted first image is formed. The eyepiece then magnifies this image. Usually the magnification of the eyepiece is fixed (either x 10 or x 10) and three rotating objective lenses are used : x 10, x 40 and x 60. The most recent development in microscope technology is the electron microscope which uses a beam of electrons instead of light. Photographic film must be used otherwise no image would be formed on the retina. This microscope has a resolution about a hundred times that of the light microscope.
57. Based on the passage, what type of image would have to be produced by the objective magnification?
(A) Either virtual or real (B) Virtual
58. Where would the first image hav e to be produced by the objective relative to the eyepiece such that a second, enlarged image would be generated on the same side of the eyepiece as the first image (first image distance = d1)?
(A)
d
iF
e (B)d
iF
e (C)2F
ed
iF
e (D)d
i 2
F
e59. Two compound microscopes A and B were compared. Both had objectives and eyepieces with the same magnification but A gave an overall magnification that was greater than that of B. Which of the following is a plausible explanation?
(A) The distance between objectiv e and eyepiece in A is greater than the corresponding distance in B. (B) The distance between objective and eyepiece in A is less than the corresponding distance is B. (C) The eyepiece and objective positions were reversed in A.
(D) The eyepiece and objective positions were reversed in B.
60. A student attempted to make a compound microscope. However, when she tried to view an object through the apparatus, no image was seen. Which of the following could explain the mishap?
I. The object distance = focal length of objective.
II. The object distance for eyepiece lens as her eyepiece. III. The student used a diverging lens as her eyepiece. IV. The student used a converging lens as her objective (A) I, II, III and IV (B) I, II, III
(C) I, II, IV (D) II, III, IV
61. The magnification of the eyepiece of a compound microscope is x15. The image height is 25 mm and the magnification of the objective is x40. What is the object height?
(A) 1.67 mm (B) 0.60 mm (C) 0.38 mm (D) 0.04 mm 62. What is the refractive power of an objective lens with a focal length of 0.50 cm?
(A) 0.2 diopters (B) 2.0 diopters (C) 20 diopters (D) 200
THE NEXT QUESTIONS REFER TO THE FOLLOWING PASSAGE
Magnification by a lens of an object at distance 10 cm from it is –2. Now a second lens is placed exactly at the same position where first was kept, without changing the distance object and lens. The magnification by this second lens is – 3.
63. Now both the lenses are kept in contact at the same place. What will be the new magnification.
(A)
13
5
(B)12
7
(C)6
11
(D)5
7
64. What is the focal length of the combination when both lenses are in contact.
(A)
60
17cm
(B)5
17cm
(C)12
7
cm
(D)13
9
cm
THE NEXT QUESTIONS REFER TO THE FOLLOWING PASSAGE
In the case of convex lens, when object is moved from f to 2f, its image is real, inverted and magnified. It moves from f to infinity on other side.
65. Focal length of a convex lens is 10 cm. When the object is moved from 15 cm to 25 cm, the magnitude of linear magnifications.
(A) will increase (B) will decrease
66. Image of object AB shown in figure will be like: F 2F A B (A) F 2F A' B' (B) F 2F A' B' (C) F 2F A' B' (D) F 2F A' B'
THE NEXT QUESTIONS REFER TO THE FOLLOWING PASSAGE
Figure shows a simplified model of the eye that is based on the assumption that all of the refraction of entering light occurs at the cornea. The cornea is a converging lens located at the outer surface of the eye with fixed focal length approximately equal to 2 cm. Parallel light rays coming from a very distant object are refracted by the cornea to produce a focused image on the retina. The retina then transmits electrical impulse along the optic nerve to the brain.
cornea
retina
Two common defects of vision are myopia and hyperopia. Myopia, sometimes referred to as nearsightedness, occurs when the cornea focuses the image of a distance object in front of the retina. Hyperopia, sometimes referred to as farsightedness, occurs when the cornea focuses the image of a nearby object behind the retina. Both of these problems can be corrected by introducing another lens in front of the eye so that the two lens system produces a focused image on the retina. If an object is so far away from the lens system that its distance may be taken as infinite, then the following relationship holds:
1
1
1
c l