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For accurate scientific work, temperatures are often measured by

A. Mercury thermometers

B. Alcohol thermometers

C. Platinum resistance thermometers

D. Thermoelectric thermometers

Answer: Option C

Solution(By Examveda Team)

The resistance of metallic conductors e.g, platinum, increases with rise of temperature . The increase in temperature results in a decrease of current which can be recorded in a galvanometer if the conductor is included in an electrical circuit. Thus the temperature can be known; platinum resistance thermometer is used generally for accurate scientific work. When two dissimilar metals are joined at the ends, and these ends are subjected to a difference of temperature, a current flows through the metals. Greater the difference of temperature , greater the current. So the curent strength can form the basis for measuring the difference in temperature. And when one of these temperatures is known, we can calculate the other.

This Question Belongs to General Knowledge >> Physics

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