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UPPCS Physics Gap Sheet: Measuring Instruments.
UPPCS has asked 24 of these. 8 have not been asked yet. Lock the first list, then read the second: it holds what UPPCS has not used yet.
First, the concept
Identify the physical quantity an instrument measures. Similar names can refer to different quantities: humidity is not liquid density, and heat is not temperature.
An instrument may measure, record or control a quantity. A barometer measures pressure, a barograph records it, and a thermostat controls temperature. Keep the function separate from the working principle.
✅ Already asked (24)
Weather and fluids
- Barometer · Measures atmospheric pressure.
- Barograph · Records atmospheric pressure over time.
- Manometer · Measures fluid pressure or a pressure difference.
- Hygrometer · Measures humidity.
- Hydrometer · Measures relative density of liquids using flotation.
- Anemometer · Measures wind speed; a wind vane shows wind direction.
- Pyrheliometer · Measures direct solar irradiance.
Heat, light and motion
- Pyrometer · A radiation pyrometer measures high temperature without touching the object.
- Calorimeter · Measures heat exchanged in a process.
- Photometer and lux meter · Photometers measure light; a lux meter measures illuminance on a surface.
- Tachometer · Measures rotational speed, commonly in revolutions per minute.
- Odometer · Records distance travelled by a vehicle.
- Sextant · Measures angular separation, such as a celestial body's altitude above the horizon.
- Seismograph · Records ground motion caused by seismic waves.
- Ringelmann chart · Visually grades the apparent darkness of smoke.
Electrical and medical instruments
- Ammeter connection · Connected in series; an ideal ammeter has zero resistance.
- Galvanometer · Detects small electric currents and their direction.
- Sphygmomanometer · Measures blood pressure.
- Stethoscope · Helps hear internal body sounds; sound undergoes reflection in its tubes.
- Audiometer · Tests hearing sensitivity at different sound frequencies.
- Electrocardiograph · Records the heart's electrical activity, not blood pressure.
Further devices and uses
- Altimeter · A pressure altimeter estimates altitude from atmospheric pressure.
- Potentiometer · A null-method potentiometer compares cell emf without drawing current from the test cell at balance.
- Auxanometer · Measures the increase in plant length over time.
❌ Not asked yet (8)
Items marked 'asked in other exams' have come in UPSC or other state exams, not yet in UPPCS.
🔒 8 items not asked yet
Weather and fluids: 1 · Electrical and medical instruments: 2 · Further devices and uses: 5
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⚠️ Hygrometer measures humidity; hydrometer measures relative density of liquids. An ammeter measures current, not power.
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