PPSC Excise and Taxation Inspector 2018 Question Paper

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22.

The instrument used for recording earthquake waves is :

A: barometer
B: hydrograph
C: pantograph
D: seismograph

The answer is: D

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Explanation

Answer: D - Seismograph

 

Explanation:

A Seismograph is the instrument used to detect, record and measure earthquake waves (seismic waves). The recorded output is called a seismogram.
It measures:

  • Magnitude of the earthquake
  • Duration of seismic waves
  • Distance of the epicentre from the recording station

 

Why other options are wrong:

  • Barometer - Measures atmospheric pressure. Used in weather forecasting.
  • Hydrograph - A graph showing river discharge/water flow over time. Not an instrument for earthquakes.
  • Pantograph - A mechanical device used for copying/scaling drawings and maps. Completely unrelated to earthquakes.

 

Scientific instruments - must know for general studies:

  • Seismograph : Earthquake waves
  • Barometer : Atmospheric pressure
  • Thermometer : Temperature
  • Hygrometer : Humidity
  • Anemometer : Wind speed
  • Rain gauge : Rainfall
  • Richter Scale : Earthquake magnitude (scale, not instrument)
  • Lactometer : Purity of milk
  • Altimeter : Altitude
  • Odometer : Distance travelled

 

Additional distinction worth knowing:

  • Seismograph = the instrument/machine
  • Seismogram = the paper record/output it produces
  • Seismology = the science of studying earthquakes
  • Richter Scale = the scale used to express earthquake magnitude