Physics Measuring Instruments

A resistance thermometer (or resistance temperature detector) measures electrical resistance of a conductor, which changes predictably with temperature. This resistance change is then used to determine temperature. It's not used for measuring salt solution concentrations or spectrum analysis.

Temperature is one of the important abiotic factor influencing plant growth. Bolometer is a temperature transducer used for the measurement of minute quantities of radiant heat.

A voltmeter is an instrument used for measuring electrical potential difference between two points in an electric circuit.

A stalagmometer is a device for investigating surface tension using the stalagmometric method. 

Ostwald viscometer is used to measure viscosity. Stalagmometer is used to measure surface tension. Sphygmomanometer is used to measure blood pressure.

A fathometer is an echo-sounding instrument used to measure water depth in oceans and lakes. It works by sending sound waves down and measuring the time for the echo to return from the seabed. Hydrometer measures liquid density, gyroscope measures orientation, and hydrophone detects underwater sounds.

A salinometer measures the concentration of salt in a solution by measuring its density. It's commonly used in marine applications, boilers, and food processing to ensure proper salinity levels.

A sphygmomanometer is the medical instrument used to measure blood pressure. The name comes from Greek 'sphygmos' (pulse) and 'manometer' (pressure meter). This is the cuff wrapped around your arm during checkups.

A lactometer is a specialized hydrometer designed to measure the density and purity of milk. It works on the principle of buoyancy - the higher the density of milk, the higher the lactometer floats. Adulterated milk with added water has lower density and causes the lactometer to sink lower. Hygrometers measure humidity, anemometers measure wind speed, and tachometers measure rotational speed.

A voltmeter measures potential difference (voltage) between two points in a circuit. A potentiometer is a variable resistor, a galvanometer detects small currents. Voltmeter is the correct answer for measuring potential difference.

Damping is a reduction in the amplitude of an oscillation as a result of energy being drained from the system to overcome frictional or other resistive forces.

A hydrophone is a microphone designed to be used underwater for recording or listening to underwater sound. Unlike microphones that detect air pressure changes, hydrophones detect pressure changes in water. They're used in marine biology, submarine navigation, seismic studies, and underwater acoustics research.

A thermometer is specifically designed to measure temperature, using principles like thermal expansion of mercury or electrical resistance. The prefix 'thermo-' relates to heat. Barometers measure atmospheric pressure, telescopes magnify distant objects, and pyrometers measure very high temperatures in industrial contexts.

A seismograph detects and records ground movements during earthquakes, creating a seismogram. The Greek root 'seismos' means earthquake or shaking. Dosimeters track radiation exposure, ammeters measure electrical current, and altimeters determine altitude above sea level.

An ammeter is an electrical instrument that measures current in amperes, its name a contraction of 'ampere meter'. Pentameter refers to poetic meter with five feet, speedometers measure velocity, and anemometers gauge wind speed.