Home
Class 11
PHYSICS
A barometer with a brass scale reads 755...

A barometer with a brass scale reads 755 mm on a day when the temperatures is `25^@C`. If the scale is correctly graduated at `0^@C`, find the true pressure at `0^@C` (in terms of height of Hg) given that the coefficient of linear expansion of brass is `18xx10^(-6)//K`. Coefficient of cubical expansion of mercury`=182xx10^(-6)//K`.

Text Solution

Verified by Experts

Given that 1 mm at `0^@C=1mm`
755 mm at `25^@C=755(1+18xx10^-6xx25)mm=755.34mm`
Let P be the value of the atmospheric pressure.
Then `P=755.34rho_(25)g=hrho_(0)g`, where `rho_(0)`,`rho_(25)` are densities of mercury at `0^@C` and `25^@C`, respectively.
or `h=755.34xx(rho_(25))/(rho_(0))=755.34xx(rho_0)/(rho_0(1+182xx10^-6xx25))`
or `h=751.19` mm
Promotional Banner

Topper's Solved these Questions

  • CALORIMETRY

    CENGAGE PHYSICS|Exercise Exercise 1.1|23 Videos

  • CALORIMETRY

    CENGAGE PHYSICS|Exercise Exercise 1.2|22 Videos

  • BASIC MATHEMATICS

    CENGAGE PHYSICS|Exercise Exercise 2.6|20 Videos

  • CENTRE OF MASS

    CENGAGE PHYSICS|Exercise INTEGER_TYPE|1 Videos

Similar Questions

Explore conceptually related problems

A barometer reads 75 cm on a steel scale. The room temperature is 30^(@)C . The scale is correctly graduated for 0^(@)C . Find the correct atmosphere pressure. Given that coefficient of linear expansion of steel is 1.1xx10^(-5).^(@)C^(-1) and that of cubical expansion of mercury is 1.8xx10^(-4).^(@)C^(-1) . Neglect expansion of glass tube.

The coefficient of linear expansion of a metal rod is 12 xx 10^(-6//0)C , its value in per ^(0)F

A barometer with a brass scale correct at 0^(@)C reads 70 cm of mercury on a day when the air temperature is 40^(@)C . The correct reading at 0^(@)C is (Coefficient of real exapansion of mercury is 0.00018//^(@)C and coefficient of linear expansion of brass is 0.00018//^(@)C)

A brass scale is graduated at 10^@C . What is the true length of a zinc rod which measures 60.00 cm on this scale at 30^@C ? Coefficient of linear expansion of brass =18xx10^-6K^-1 .

(a) The brass scale of a barometer gives correct reading at 0^(@)C . Coefficient of linear expansion of brass is 2.0xx10^(-5)//^(@)C . The barometer reads 75cm at 27^(@)C . What is the atmospheric pressure at 27^(@)C ? (b) A barometer reads 75.0cm on a steel scale. The room temperature is 30^(@)C . The scale is correctly graduated for 0^(@)C . The coefficient of linear expansion of steel is alpha=1.2xx10^(-5)//^(@)C and the coefficient of volume expansion of mercury is gamma=1.8xx10^(-4)//^(@)C . Find the correct atmospheric pressure.

A Barometer with brass scale, which is correct at 0^(@)C , reads 75cm on a day when the air temperature is 20^(@)C . Calculate correct reading at 0^(@)C . (Coefficient of real expansion of mercury =0.00018//^(@)C and coefficient of linear expansion of brass =0.000189//^(@)C .)

A glass bulb of volume 250c c is filled with mercury at 20^(@)C and the temperature is raised to 100^(@)C . If the coefficient of linear expansion of glass is 9 xx 10^(-6 //@)C ). Coefficient of absolute expansion of mercury is 18 xx 10^(-5 //@)C ). The volume of mercury overflows