Geometric Optics – Principles of Geometric Optics – EN
Geometric Optics
Principles of Geometric Optics
01- (ENEM-MEC)
The diagram below represents, in a schematic and simplified way, the distribution of energy from the Sun over the atmosphere and the Earth’s surface. In the area delimited by the dashed line, some processes involved in the flow of energy in the atmosphere are highlighted.
Rain is the natural phenomenon responsible for maintaining adequate water levels in hydroelectric plant reservoirs. This phenomenon, like the entire hydrological cycle, depends heavily on solar energy. Of the numbered processes in the diagram, the one that is most directly related to the level of hydroelectric plant reservoirs is number 1.
02-(ENEM-MEC)
The figure below shows a solar eclipse at the moment it is photographed from five different points on the planet.
Three of these photographs are reproduced below.
The photos could correspond, respectively, to the points:
a) III, V and II
b) II, III and V
c) II, IV and III
d) I, II and III
e) I, II and V
03-(ENEM-MEC)
Gilberto Gil uses the compound word LIGHT YEARS in the lyrics of the song. The practical meaning, in general, is not necessarily the same as in science. In Physics, a light year is a measurement that relates the speed of light and the time of a year and which, therefore, refers to
04-(ENEM-MEC)
The comics show, through the projection of the shadow of the tree and the boy, the sequence of periods of the day:
morning, midday and evening, which is determined
a) by the vertical position of the tree and the boy.
b) by the boy’s position in relation to the tree.
c) by the apparent movement of the Sun around the Earth.
d) by the specific time zone of each point on the Earth’s surface.
e) by the season, with days being shorter in winter than in summer.
Exercises with Enem characteristics
05-(UNIFAL-MG)
Three beams of light, of the same intensity, can be seen crossing a room, as shown in the figure.
Beam 1 is red, beam 2 is green and beam 3 is blue. The three beams intersect at position A and hit the screen in regions B, C and D. The colors that can be seen in regions A, B, C and D, respectively, are:
a) white, white, white and white
b) white, red, green and blue
c) yellow, blue, green and red
d) white, blue, green and red
e) yellow, red, green and blue
06-(UFMG-MG)
Marília and Dirceu are in a square lit by a single lamp. Select the alternative in which
the beams of light that allow Dirceu to see Marília are correctly represented.
07-(FGV-SP)
The basement of an old house has a narrow square skylight measuring 100 cm2 in area, which allows light from outside to enter and is diffusely reflected by the surrounding buildings. In the illustration, we see a spider, a mouse and a cat standing on the same vertical plane that intersects the center of the refrigerator and the center of the skylight.
Since the skylight is the light source, it can be said that, due to the interposition of the refrigerator, the spider, the mouse and the cat, in that order, are in regions of:
a) light, light and shadow.
b) twilight, light and twilight.
c) shadow, twilight and light.
d) light, shadow and twilight.
e) penumbra, shadow and shade
08-(UNESP-SP)
When the Sun is overhead, a girl places a pencil 7.0.10 -3 m in diameter parallel to the ground and observes the shadow it casts due to the sunlight.
He notices that the shadow of the pencil is very clear when it is close to the ground, but as he raises the pencil, the shadow loses sharpness until it disappears, leaving only the penumbra. Knowing that the diameter of the Sun is 14.10 8 m and the distance from the Sun to the Earth is 15.10 10 m, determine the height of the pencil in relation to the ground when the shadow disappears.
09-(FUVEST-SP)
On a cloudless day, at noon, the shadow projected on the ground by a sphere 1 cm in diameter is
very clear if it is 10cm from the ground. However, if the sphere is 200cm from the ground, the shadow is very unclear. It can be stated that the main cause of the observed effect is that:
a) the Sun is an extensive source of light
b) the refractive index of air depends on the temperature
c) light is a wave phenomenon
d) sunlight contains different colors
e) the diffusion of light in the air “blurs” the shadow
10-(CESGRANRIO-RJ)
At 6:00 p.m., a person looks up at the sky and sees that half of the Moon is illuminated by the Sun. Since this is not a lunar eclipse, it is correct to say that the Moon’s phase at that moment is:
a) it can only be a first quarter moon
b) it can only be a last quarter moon
c) it can only be a full moon
d) it can only be a New Moon
e) it can be a waxing quarter or a waning quarter
11-(FGV-SP)
The following verses recall a time when the city of São Paulo had gas lighting:
When a “blue-green light” shines on a red card, the color of the absorbed light is:
a) green and the reflected one is blue
b) blue and the reflected one is green
c) green and the reflected one is red
d) blue-green and none is reflected
e) blue and the reflected one is red
12-(PUCCAMP-SP)
A person stands in front of a dark chamber, 2 m from the opening of the chamber and his
image that forms in the background is 6 cm high. For it to be 4 cm high, this person, in relation to the camera, must
a) move away 1 m.
b) move 2 m away.
c) move 3 m away.
d) approach 1 m.
e) approach 2m
13-(FUVEST-SP)
A certain optical assembly consists of a screen, a mask with a triangular hole and three lamps, L 1 , L 2 and L 3 , as shown in the following figure. L 1 and L 3 are small flashlight lamps and L 2 is a lamp with a long, linear filament, but small in other dimensions. The diagram shows the image projected on the screen with only L 1 lit.
The sketch that best represents the bulkhead illuminated by the three lit lamps is
