Practice Test 5 - LTDH - Reading 1

Practice Test 5 - LTDH - Reading 1

Open Ended

What are other uses of electricity?

Open Ended

What can generate electricity?

Multiple Choice

Cars hesitate in the streets because there are no traffic lights to guide them

Multiple Choice

Cars hesitate in the streets because there are no traffic lights to guide them, and food spoils in silent refrigerators.

Multiple Choice

the strength of the shock it can deliver corresponds roughly to the length of its body

Multiple Choice

certain muscle cells have become so specialized as electrical generators that they do not work work as muscle cells at all.

The modern age is the age of electricity. People are so used to electric lights, radio, televisions, and telephones that it is hard to imagine what life would be like without them. When there is a power failure, people grope about in flickering candlelight. Cars hesitate in the street because there are no traffic lights to guide them, and food spoils in silent refrigerators.

Yet, people began to understand how electricity works only a little more than two centuries ago. Nature has apparently been experimenting in this field for millions of years. Scientists are discovering more and more that the living world may hold more interesting secrets that could benefit humanity.

Multiple Choice

What is the main idea of the passage

• People would be at a loss without electricity

• Scientists still have much to discover about electricity

Multiple Choice

The author mentions all of the following as results of a blackout EXCEPT that

• refrigerator food items may go bad

• traffic lights do not work

• people must rely on candlelight

• elevators and escalators do not function

All living cells sent out pulses of electricity. As the heart beats, it sends out pulses of recorded electricity; they form an electrocardiogram, which a doctor can study to determine how well the heart is working. The brain, too, sends out brainwaves of electricity, which can be recorded in an electroencephalogram. The electric currents generated by most living cells are extremely small - often so small that sensitive instruments are needed to record them. But in some animals, certain muscle cells have become so specialized as electrical generators that they do not work as muscle cells at all. When large number of these cells are linked together, the effects can be astonishing.

The electric eel is an amazing storage battery.

Multiple Choice

Why does the author mention electric eels?

• To warn reader to stay away from them

• To compare their voltage to that used in houses

• to give an example of living electrical generator

• to describe a new source of electrical power

The electric eel is an amazing storage battery. It can send a jolt of as much as 800 volts of electricity through the water (An electric house current is only 120 volts). As many as four-fifths of all the cells in the electric eel's body are specialized for generating electricity, and the strength of the shock it can deliver corresponds roughly to the length of its body.

Multiple Choice

It can be infered from the passage that the longer the an eel is the...

• more beneficial it will be to science

• more powerful will be its electrical charge

• easier it will be to find

• tougher it will be to eat

Multiple Choice

According to the passage, how many volts of electricity can an electric eel emit?

• 1000

• 800

• 200

• 120

Multiple Choice

The author mentions all of the following as results of a blackout EXCEPT that

• refrigerator food items may go bad

• traffic lights do not work

• people must rely on candlelight

• elevators and escalators do not function