Eduqo
General Science›Ch 1: Physics›Scientific Instruments & Inventors
Master key devices, measurements, and creators for competitive exams
Every scientific instrument measures a specific physical property using fundamental scientific principles. Memorize the exact physical quantities measured by barometer, hygrometer, and lactometer to secure direct marks in SSC and railway exams.
Smart Memory Hooks
| Instrument | Physical Quantity | Inventor / Note |
|---|---|---|
| Barometer | Atmospheric pressure | Evangelista Torricelli |
| Hygrometer | Relative humidity | Horace Bénédict de Saussure |
| Lactometer | Purity of milk | Dicas |
| Seismograph | Earthquake waves | Luigi Palmieri |
Ammeter
(Measures electric current)
Measures electric current
Connected in series inside an electrical circuit.
Voltmeter
(Measures potential difference)
Measures potential difference
Connected in parallel across circuit components.
Seismograph
(Records seismic tremors)
Records seismic tremors
Detects ground motion during earthquakes.
Dynamo
(Converts mechanical energy)
Converts mechanical energy
Invented by Michael Faraday to generate electricity.
Hydrometer measures humidityHygrometer measures humidity
Hydrometer measures liquid density, whereas Hygrometer measures atmospheric humidity.
Ammeter is connected in parallelAmmeter is connected in series
An ammeter has low resistance and must be placed in series to measure total current flow.
Barometer invented by Torricelli for wind speedBarometer measures atmospheric pressure
Torricelli's barometer measures air pressure variations, not wind speed or rainfall.
Q1.Which instrument is used to measure atmospheric humidity?
Q2.Who invented the mercury barometer?