Physics Measuring Instruments

An anemometer is the specialized meteorological instrument used to measure wind speed. Barometers measure atmospheric pressure, hygrometers measure humidity, and thermometers measure temperature. The anemometer has cups or vanes that rotate with the wind, and the rotation speed is calibrated to wind velocity.

The Parliament passed the Legal Metrology Bill, 2008 recently. It provides for regulation of weight or measure used in transactions; approval of model of weight or measure; verification of prescribed weight or measure by government approved test centre; exempting regulation of weight or measure or other goods meant for export; levy of fees for various services; nomination of a director by a company who will be responsible for complying with the provisions of the enactment; penalty for offences and appeal against decision of various authorities.

This is the correct option. An electroscope a device used to detect electric charge on an object.

This is the correct option. A seismograph is an instrument that measures and records the magnitude of an earthquake in terms of the shockwaves it produces.

A hydrometer is an instrument specifically designed to measure the density (or specific gravity) of liquids, floating higher in denser liquids and lower in less dense ones based on Archimedes' principle. It is commonly used to test battery fluid, urine specific gravity, and alcohol concentration in brewing.

Pycnometer

A chronometer is a precise timekeeping instrument, essentially a highly accurate clock. It specifically measures time. The other options are incorrect: sound waves are measured by oscillosodes or frequency meters, water waves by wave height/length analyzers, and color contrast by photometry tools.

Alcohol thermometers are used to measure very low temperatures because alcohol has a lower freezing point (-114°C) compared to mercury (-39°C). This makes alcohol thermometers suitable for measuring temperatures in cold environments.

The correct matching is: Anemometer - fluid velocity (measures wind/air speed), Tachometer - rotation speed (measures rotational speed), Pyrometer - high temperatures (measures very high temperatures), Dynamometer - machine power (measures force/torque/power). This gives IV-A, III-B, I-C, II-D.

A hydrometer is an instrument used to measure the specific gravity (relative density) of liquids. It floats at different levels depending on the liquid's density and is commonly used to check battery electrolyte, alcohol content, or urine specific gravity.

The instrument used to note the BP of a person is Sphygmomanometer.

A hygrometer is an instrument specifically designed to measure the relative humidity of air - the amount of water vapor present. Density is measured by a hydrometer, vapour pressure by a manometer, and voltage by a voltmeter.

A voltmeter is specifically designed to measure voltage or potential difference between two points in an electrical circuit. Option A is correct. Dynamo generates electricity, ammeter measures current, and manometer measures pressure.

A lactometer is specifically designed to measure the specific gravity of milk, which indicates its purity and detects adulteration (like added water). Calorimeters measure heat energy, barometers measure atmospheric pressure, and photometers measure light intensity.

A sphygmomanometer is the medical instrument used to measure blood pressure. It consists of an inflatable cuff and a pressure gauge. The name comes from Greek 'sphygmos' (pulse) and 'manometer' (pressure meter). Density is measured by densitometers, humidity by hygrometers.