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A barometer reads 75cm on steel scale when room temperature is 30 degree Celsius. The scale is graduated at 0 degree Celsius. Find correct atmospheric pressure if coefficient of linear expansion of steel=10^-5(10 raise to power -5)/C and coefficient of volumetric expansion of mercury is 1.8*10^-3 /C
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A barometer reads 75cm on steel scale when room temperature is 30 degr...
Given:
- Room temperature (T1) = 30°C
- Barometer reading on steel scale (H1) = 75 cm
- Coefficient of linear expansion of steel (αsteel) = 10^-5 /°C
- Coefficient of volumetric expansion of mercury (βmercury) = 1.8 * 10^-3 /°C

To Find:
- Correct atmospheric pressure

Formula:
The relationship between the change in height of a liquid column in a barometer and the change in temperature is given by:
ΔH = H2 - H1 = βL(T2 - T1)
Where,
ΔH = Change in height of liquid column
H2 = Final height of liquid column
H1 = Initial height of liquid column
βL = Coefficient of linear expansion of liquid
T2 = Final temperature
T1 = Initial temperature

Approach:
1. Convert the given barometer reading from the steel scale to the mercury scale.
2. Use the given coefficient of linear expansion of steel to find the change in height of the liquid column due to the change in temperature.
3. Convert the change in height back to the steel scale using the coefficient of volumetric expansion of mercury.
4. Calculate the correct atmospheric pressure.

Calculation:
1. Conversion to Mercury Scale:
The length of the mercury column at 0°C is 76 cm on the steel scale. Since the steel scale is graduated at 0°C, the mercury column reading on the steel scale is the same as on the mercury scale at 0°C.

2. Change in Height of Liquid Column:
Using the formula, ΔH = H2 - H1 = βL(T2 - T1)
ΔH = (H2 - H1) / βL = (76 - 75) / (10^-5) = 10^5 cm/°C

3. Conversion back to Steel Scale:
The change in height of the liquid column is in mercury scale units. To convert it back to the steel scale units, we divide by the coefficient of volumetric expansion of mercury:
ΔH' = ΔH / βmercury = 10^5 cm/°C / (1.8 * 10^-3 /°C) = 5.56 * 10^7 cm/°C

4. Calculation of Correct Atmospheric Pressure:
The atmospheric pressure can be calculated by subtracting the change in height from the initial barometer reading:
P = H1 - ΔH' = 75 cm - 5.56 * 10^7 cm/°C = -5.56 * 10^7 cm/°C

Answer:
The correct atmospheric pressure is -5.56 * 10^7 cm/°C.
Community Answer
A barometer reads 75cm on steel scale when room temperature is 30 degr...
74.89cm
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A barometer reads 75cm on steel scale when room temperature is 30 degree Celsius. The scale is graduated at 0 degree Celsius. Find correct atmospheric pressure if coefficient of linear expansion of steel=10^-5(10 raise to power -5)/C and coefficient of volumetric expansion of mercury is 1.8*10^-3 /C
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A barometer reads 75cm on steel scale when room temperature is 30 degree Celsius. The scale is graduated at 0 degree Celsius. Find correct atmospheric pressure if coefficient of linear expansion of steel=10^-5(10 raise to power -5)/C and coefficient of volumetric expansion of mercury is 1.8*10^-3 /C for JEE 2024 is part of JEE preparation. The Question and answers have been prepared according to the JEE exam syllabus. Information about A barometer reads 75cm on steel scale when room temperature is 30 degree Celsius. The scale is graduated at 0 degree Celsius. Find correct atmospheric pressure if coefficient of linear expansion of steel=10^-5(10 raise to power -5)/C and coefficient of volumetric expansion of mercury is 1.8*10^-3 /C covers all topics & solutions for JEE 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A barometer reads 75cm on steel scale when room temperature is 30 degree Celsius. The scale is graduated at 0 degree Celsius. Find correct atmospheric pressure if coefficient of linear expansion of steel=10^-5(10 raise to power -5)/C and coefficient of volumetric expansion of mercury is 1.8*10^-3 /C.
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