VCR Lesson 5

Suhas Dundigalla

Fill in the blank with the most appropriate word from Lesson 5.

The Lexus hoverboard uses superconductors, electromagnets and a cooling agent such as liquid nitrogen to ________.
Big image

Word

Levitate (tr. and intr. v.)


To rise or float, or cause to rise, seemingly despite gravity.


Levitation (n.)

Roots

Levis (L.) "light"

Synonyms

float

hover

rise

glide

soar

fly

Antonyms

Anything pertaining to being on the ground.

Maglev

Maglev trains use magnetic levitation to move without ever touching the ground. With virtually no friction, maglev trains are capable of moving at very high speeds. These trains use magnets to levitate and propel themselves. Although a prototype was demonstrated in 1913, it took another 66 years until 1979 for the first maglev to be authorized for public transportation.


Maglev trains do not have an engine. Magnets within the track as well as the underside of the train cause the train to move. The magnetized coil in the track repels the underside of the train causing it to levitate above the track. Once the train is levitating, power is sent to the coils to create magnetic fields that push and pull the train. The polarity is rapidly switched back and forth so that the coil in front pulls, while the coil behind pushes thereby creating propulsion.

Choose the letter of the sentence in which the word in the bold-faced type is used incorrectly.

a. Maglev trains levitate over the tracks through the use of magnets, reducing friction and increasing travel speeds greatly.

b. Levitation can not only be achieved with magnets but also through the use of air pressure or a stream of air.

c. The levitation of small live animals with high water content has also been achieved through the use of very powerful electromagnets due to the diamagnetic repulsion of body water.

d. The hummingbird levitated over the flowers as it drank the nectar inside.

The choice with the bold word used incorrectly is D.