PrepTest 134, Section 2, Question 7
Inertia affects the flow of water pumped through(57 more words not shown)
The information above provides the(8 more words not shown)
- AThe rate at(8 more words not shown)
- BThe flow of(7 more words not shown)
- CInertia in the(17 more words not shown)
- DElectrical engineers try(9 more words not shown)
- EWhen a water(14 more words not shown)
Reading the argument
The water doesn't instantly reach full speed when the pump starts, and it doesn't instantly stop when the pump shuts off. Inertia makes those changes gradual: water at rest resists starting to move, and moving water tends to keep moving.
You can picture the flow building up after a hose is turned on. Electrical current is harder to watch in that way. But we don't need to see it ourselves or know the physics of inductance. The passage supplies the comparison: inductance affects an electrical circuit in a way similar to inertia's effect on water in pipes.
What we’re looking for
So carry the roles across. Inertia affects the water's flow; inductance should affect the electrical current's flow. That is the modest consequence I'd look for in an answer. The comparison doesn't tell us that the two effects are identical in every detail.
Working the answers
- ACorrect
The passage describes inertia changing how quickly water reaches full flow and how gradually that flow decreases. A similar effect in electrical circuits supports saying that inductance affects the rate at which current flows. A preserves the relationship while substituting electrical current for water and inductance for inertia.
- B
Similar effects don't make inertia a requirement for electrical current. The passage assigns inertia to the water example and inductance to the electrical example. B imports the water example's term into the electrical system and adds a requirement the passage never states.
- C
This turns a comparison between two systems into a claim that one system causes the effect in the other. Nothing says inductance in a pump's circuitry causes the inertia of its water. The argument would make the same comparison without telling us whether the water pump was electrically powered at all.
- D
We aren't told what electrical engineers try to do. They might want to reduce inductance in some circumstances or take advantage of it in others. A description of an effect doesn't establish the professionals' goals concerning that effect.
- E
Continuing to flow isn't the same as continuing to be pumped. Water already in motion could keep moving after the pump stops doing any work. E also supplies a duration of one or two seconds, while the passage only says the decrease is gradual. Neither the continued pumping nor that specific timing is established.
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