PASSAGE 3

An earthquake comes like a thief in the night, without warning. It was necessary, therefore, to invent instruments that neither slumbered nor slept. Some devices were quite simple. One, for instance, consisted of rods of various lengths and thicknesses which would stand up on end like ninepins. When a shock came it shook the rigid table upon which these stood. If it were gentle, only the more unstable rods fell. If it were severe, they all fell. Thus the rods by falling and by the direction in which they fell, recorded for the slumbering scientist, the strength of a shock that was too weak to waken him and the direction from which it came.

But, instruments far more delicate than that were needed if any really serious advance was to be made. The idea to be aimed at was to devise an instrument that could record with a pen on paper, the movements of the ground or of the table, as the quake passed by. While I write my pen moves but the paper keeps still. With practice, no doubt, I could, in time, learn to write by holding the pen still while the paper moved. That sounds a silly suggestion, but that was precisely the idea adopted in some of the early instruments (seismometers) for recording earthquake waves. But when table, pen-holder and paper are all moving how is it possible to write legibly? The key to a solution of that problem lay in an everyday observation. Why does a person standing in a bus or train tend to fall when a sudden start is made? It is because his feet move on, but his head stays still.

1. The passage says that early instruments for measuring earthquakes were
A) faulty in design
B) expensive
C) not sturdy
D) not sensitive enough

2. Why was it necessary to invent instruments to observe an earthquake?
A) Because an earthquake comes like a thief in the night
B) To make people alert about earthquakes during their conscious as well as unconscious hours
C) To prove that we are technically advanced
D) To experiment with the control of man over nature

3. A simple device which consisted of rods that stood up on end like ninepins was replaced by a more sophisticated one because it failed
A) to measure a gentle earthquake
B) to measure a severe earthquake
C) to record the direction of the earthquake
D) to record the facts with a pen on paper

4. The everyday observation referred to in the passage relates to
A) a moving bus or train
B) the sudden start of a bus
C) the tendency of a standing person to fall when a bus or train moves suddenly
D) people standing in a bus or train

5. The early seismometers adopted the idea that in order to record the earthquake, it is
A) the pen that should move just as it moves when we write on paper
B) the pen that should stay still and the paper should move
C) both pen and paper that should move
D) neither pen nor paper that should move

Solution with explanation

Answer Key

Solution with explanation

1. Option ‘D’ (not sensitive enough). Sensitive equipment is able to record small changes; e.g. The patient’s responses are recorded on a sensitive piece of equipment which gives extremely accurate readings.

2. Option ‘A’ (Because an earthquake comes like a thief in the night). The first two sentences of the passage are good enough to know the answer. SLUMBER = to go in an inactive state.

3. Option ‘D’ (to record the facts with a pen on paper). The answer lies in the first two lines of the second paragraph.

5. Option ‘B’ (the pen that should stay still and the paper should move). The answer lies in the extract taken from the second paragraph — With practice, no doubt, I could, in time, learn to write by holding the pen still while the paper moved. That sounds a silly suggestion, but that was precisely the idea adopted in some of the early instruments (seismometers) for recording earthquake waves.