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` (interms 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`.

A barometer with a brass scale reads 755 mm on a day when the temperat

1.	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` (interms 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`.
Answer» 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

Discussion

No Comment Found

Related InterviewSolutions

A sinker of weight `w_0` has an apparent weight `w_1` when weighed in a liquid at a temperature `t_1 and w_2` when weight in the same liquid at temperature `t_2`. The coefficient of cubical expansion of the material of sinker is `beta`. What is the coefficient of volume expansion of the liquid.
Consider two rods of same length and different specific heats (`S_1` and `S_2`), conductivities `K_1` and `K_2` and area of cross section (`A_1` and `A_2`) and both having temperature `T_1` and `T_2` at their ends. If the rate of heat loss due to conduction is equal thenA. `K_1A_1=K_2A_2`B. `K_2A_1=K_1A_2`C. `(K_1A_1)/(S_1)=(K_2A_2)/(S_2)`D. `(K_2A_1)/(S_2)=(K_1A_2)/(S_1)`
If heat is supplied to a solid, its temperature (a) must increase (b) may increase (c) may remain constant (d) may decrease.
If head a supplied to a solid, its temperatureA. must increaseB. may increaseC. may remain constantD. may decrease
A copper block of mass `60kg` is heated till its temperature is increased by `20^(@)C` Find the head supplied to the block specific head capacity of `= 0.09 cal g^(-1)^(@)C`
In an industrial process 10 kg of water per hour is to be heated from `20^@C` to `80^@C`. To do this steam at `150^@C` is passed from a boiler into a copper coil immersed in water. The steam condenses in the coil and is returned to the boiler as water at `90^@C`. How many kilograms of steam is required per hour (specific heat of steam`=1 cal//g^@C`, Latent heat of vapourization`=540 cal//g`)?
Water at `0^@C` was heated until it started to boil and then until it all changed to steam. The time required to heat water from `0^@C` to `100^@C` is 5 min and the time to change boiling water to steam is 28 minutes. If the flame supplied heat at a constant rate, the specific latent heat of vaporisation of water (neglecting heat losses, container etc. is (in `J//g`). (specific heat of water s `=4.2 J//g` )A. 540B. 2268C. 2352D. 2356
A ball is droped as a floor from a height of `2.0m` After the collsion it rises up to a height of `1.5m` Assume thet `40%` of the machanical energy lost goes as thermal energy into the ball.Calculate the rise in the temperature of the ball in the colliation headcapacity of the ball is `800J K^(-1)`
Name three fossil fuels that emit carbon dioxide into the atmosphere
With the increase in carbon dioxide in the atmosphere the acidity of oceans will : (a) decrease (b) remain unaffected (c) increase (d) none of these

Discussion

No Comment Found

Related InterviewSolutions

Reply to Comment