Latest Physical Science Reviewer 4 - LET EXAM - Questions & Answers

Welcome to LET Exam Questions and Answers!!!

Latest Physical Science Reviewer 4


1. The polarization behavior of light is BEST explained by considering light to be __________.
A. particles
B. transverse waves
C. longitudinal waves
D. unpolarized

Ans: B. Transverse waves
Polarized Light, light in which individual light waves are aligned parallel to one another. The fact that light can be polarized shows that it is made up of transverse waves, because only transverse waves can be polarized.

2. Which type of light is vibrates in a variety of planes?
A. Electromagnetic
B. Polarized
C. Transverse
D. Unpolarized

Ans: D. Unpolarized
-A light wave that is vibrating in more than one plane is referred to as unpolarized light. Light emitted by the sun, by a lamp in the classroom, or by a candle flame is unpolarized light. Such light waves are created by electric charges that vibrate in a variety of directions.

3. Light is passed through a filter whose transmission axis is aligned horizontally. It then passes through a second filter whose transmission axis is aligned vertically. What will happen to the light after passing through both filters?
A. It will be polarized
B. It will be un polarized
C. It will be entirely blocked.
D. It will return to its original state.

Ans: C. It will be entirely blocked.
-Two polarized filters placed one in front of the other will block all light when one is rotated so that its filtered axis is perpendicular to the filtered axis of the other filter.

4. Light rays enter a material and scatter. Which BEST describes what happens to the light rays.
A. Bounce straight back
B. Move straight through
C. Spread out in all direction
D. Move through but in a new direction

Ans: C. Spread out in all directions
-A transluscent material looks cloudy because light rays passing through are scattered in all directions.

5. The energy generated by the suns travels to Earth as electromagnetic waves of varying lengths. Which statement correctly describes an electromagnetic wave with a long wavelength?
A. It has a high frequency and low energy.
B. It has a high frequency and high energy.
C. It has a low frequency and can travel through a vacuum.
D. It has a low frequency and needs a medium to travel through.


Ans: C. It has a low frequency and can travel through a vacuum.
-A light wave that has a longer wavelength will have a lower frequency because each cycle takes a longer time to complete.

6. Why is the sky blue?
A. It reflects the color of the ocean
B. The color of the outer space is blue.
C. Blue light is more readily scattered than red light by nitrogen.
D. Red light is scatted more easily than blue light by dust particles.

Ans: C. Blue light is more readily scattered than red light by nitrogen.
-Our Earth atmosphere predominately contains nitrogen and oxygen molecules. These atoms behave like tiny optical tuning forks and selectively scatter light waves of appropriate frequencies. The natural frequencies that nitrogen and oxygen resonate with the sunlight are in the ultraviolet part of the white light solar spectrum. Visible violet and blue light has a frequency close to ultraviolet frequencies so there are considerable forced vibrations, and therefore, blue light scatters in our atmosphere in large amounts.

7. What human activity has added the most carbon in the atmosphere?
A. Burning fossils fuels
B. Mining fossil fuel
C. Increasing soil erosion
D. Cutting down the rainforests

Ans: A. Burning of fossil fuels
-The recent phenomenon of global warming has been attributed primarily to increasing atmospheric CO2 concentrations in Earth’s atmosphere. The global annual mean concentration of CO2 in the atmosphere has increased markedly since the Industrial Revolution, From 280 ppm as of 2013, with the increase largely attributed to the burning of fossil fuels.

8. Which of the following BEST describes the image for a thin diverging lens that forms whenever the magnitude of the object distance is less than that of the lens’ focal length?
A. Inverted, reduced, and real
B. Inverted, enlarged, and real
C. Upright, reduced, and virtual
D. Upright, enlarged and virtual

Ans: C. Upright, reduced, and virtual
-Unlike converging lenses, diverging lenses always produce virtual images, upright, reduced in size and located on the object’s side of the lens. The location of the object does not affect the characteristics of the image.

9. Acid rain is formed when sulfur oxides react with water in air. It causes lakes and streams decrease in pH which makes it unable to support fish and plant life. Which is the LEAST means of solving this problem?

A. Limestone may be added to the water basins.
B. Neutralize sulfur oxides with basic compounds.
C. Reduction of sulfur emissions from the industrial establishments.
D. Providing absorbent colloidal materials to screen acid rain before hitting the water.

Ans: D. Providing absorbent colloidal materials to screen acid rain before hitting the water.
-Option D does not prevent acid rain at all. It only prevents temporarily the acid rain from penetrating the water.


10. Which of the following would decrease the rate in which a solid dissolves in a liquid?

A. Supersaturating the solution
B. Applying pressure into the solution
C. Grinding the solid into smaller pieces
D. Increasing the temperature of an exothermic reaction

Ans: D. Increasing the temperature of an exothermic reaction
-Increasing the temperature results in a stress on the products side from the additional heat. Le Chatelier’s principle predicts that the system shifts toward the product side in order to alleviate this stress. By shifting towards the reactant side, less of the solid is dissociated when equilibrium is again established, resulting I decreased solubility.


11.Which factors affects the rate of dissolution when powdered sugar dissolves more rapidly than granulated sugar?

A. Application of heat
B.  Nature of solute
C. Particle size
D. Stirring

Ans: C. Particle size
-Granulated sugar is larger than powdered sugar. The larger the molecules of the solution are, the more difficult it is for the solvent molecules to surround bigger molecules.


12. What is the physical evidence that the core is composed mostly in iron?
A. Volcanoes regularly erupt material from the core to the surface.
B. Scientist have sampled the core and determined its composition.
C. The known mass of Earth requires material of high density at the core.
D. A and B

Ans: The known mass of the Earth requires material of high density at the core.
-That material must be dense: it must be denser than the mantle, and it must be dense enough to account for the rest of the mass of the Earth. Since the core make up about one-third of the Earth’s mass it must be material is common in the solar system. It must account for the observed seismic velocities. It should also be a material with magnetic properties to account for the Earth’s magnetic field. Iron is the obvious candidate.

13. Which of the following comprised the largest portion of Earth’s volume?
A. Crust
B. Inner core
C. Mantle
D. Outer core

Ans: C. Mantle
-The mantle is almost 2900 kilometers thick and comprises about 83% of the Earth’s volume.

14. Which of the following statements about the Mohorovicic discontinuity is False?
A. The Moho separates the crust from the mantle.
B. The Moho marks the top of a partially molten layer.
C. The Moho separates denser rocks below from less dense rocks above.
D. Seismic wave speeds up as they pass across the Moho heading downward.

Ans: B. The Moho marks up the top of a partially molten layer.
-The Mohorovicic Discontinuity, or “Moho”, is the boundary between the crust and the mantle. Choices A, C, and D are true information about Moho.

25. Where do P waves travel fastest?
A. Upper mantle
B. Lower mantle
C. Outer core
D. Inner core

Ans: B. Lower mantle
-P-waves are the first waves to arrive on a complete record of ground shaking because they travel the fastest. They typically travel at speeds between 1  and 14 km/sec. The slower vale corresponds to a P-waves traveling is water, the higher number represents the P-wave speed near the base of Earth’s mantle.

16. What is the driving force for the movement of the lithospheric plates?
A. Heat from the sun
B. Heat in the atmosphere
C. Unequal distribution of heat within the Earth
D. Unequal distribution of heat in the oceans

Ans: C. Unequal distribution of heat within the Earth
-The driving force for the movement of lithosphere plates is convection currents. These currents are found in the inner core of the Earth and take the heat from the core to the lithosphere. Tectonic plates are able to move because of the relative density of oceanic lithosphere and the relative weakness of the original source of energy driving plate tectonics.

17. Which evidence supports Alfred Wegener’s Continental Drift Theory?
A. Major rivers on different continents match
B. Land bridge still exist that connect major continents
C. The same magnetic direction exist on different continents
D. Fossils of the same organism have been found on different continents

Ans: D. Fossils of the same organism have been found on different continents
-Eduard Suess was an Austrian geologist who first realized that there had once been a land bridge connecting South America, Africa, India, Australia, and Antarctica. He named this large land mass Gondwanaland (named after a district in India where the fossil plant Glossopteris was found). This was the southern supercontinent formed after Pangaea broke up during the Jurassic period. Suess based his deductions on the fossil plant Glossopteris, which is found throughout India, South America, South Africa, Australia, and Antarctica. Fossils of Mesosaurus (one of the first marine reptiles, even older than the dinosaurs) were found in both South America and South Africa.

18. Which of the following is TRUE based on the Plate Tectonics Theory?
A. The asthenosphere is strong and rigid.
B. The lithosphere is divided into plates.
C. The asthenosphere is divided into plates.
D. The asthenosphere moves over the lithosphere.

Ans: B. The lithosphere is divided into plates.
-Plate tectonics is the theory that outer rigid layer of the earth (the lithosphere) is divided into a couple of dozen “plates” that move around across the Earth’s surface relative to each other, like slabs of ice on a lake.

19. What type of boundary occurs where two plates move together, causing one plate to descend into the mantle beneath the outer plate?
A. Convergent boundary
B. Divergent boundary
C. Transform fault boundary
D. Transitional boundary

Ans: A. Convergent boundary
-In plate tectonic, a convergent boundary is an actively deforming region where two (or more) tectonic plates or fragments of the lithosphere move toward one another and collide. As a result of pressure, friction, and plate material melting in the mantle, earthquakes and volcanoes are common near convergent boundaries. When two plates move towards one another, they form either a subduction zone or a continental collision. This depends on the nature of the plates involved. In a subduction zone, the subducting plate, which is normally a plate with oceanic crust, moves beneath the other plate, which can be made of either oceanic or continental crust.

20. Which are considered as most destructive earthquake waves?
A. P waves
B. Q waves
C.  S Waves
D. Surface waves

Ans: D. Surface waves
-Travelling only through the crust, surface waves are of a lower frequency than body waves, and are easily distinguished on a seismogram as a result. Though they arrive after body waves, it is surface waves that are almost entirely responsible for the damage and destruction associated with earthquakes. This damage and the strength of the surface waves are reduced in deeper earthquakes.

To download this reviewer, just click here. Good luck and God bless!

No comments:

Post a Comment

Related Posts