You visited us 4 times! Enjoying our articles? Unlock Full Access!

Byju's Answer

Standard XII

Physics

Atmospheric Pressure

The brass sca...

Question

The brass scale of a barometer gives correct reading at $0^{o} C$ . The barometer reads $75 c m$ at $27^{o} C$ . what is the correct atmospheric pressure at $27^{o} C$ . Tne coefficient of linear expansion $α$ of brass is $2.0 \times 10^{- 5}$ degree/celcius

Open in App

Solution

$L_{o}$ = 75cm

α = $\frac{20 \times 10^{- 6}}{d e g r e e - c e l c i u s}$

$Δ T$ = 27 – 0 = 27 degree-celsius

L = ?

# Formula-

We'll use the formula for the coefficient of linear expansion

$L = L_{o} (1 + a Δ T)$

$L = 75 (1 + 20 \times 10^{- 6} \times 27)$

$L = 75 (1 + 0.00054)$

$L = 75 \times 1.00054$

$L = 75.0405 c m$

Atmospheric pressure at
$27^{0}$ is $75.0405$ cm of brass.

Suggest Corrections

Similar questions

Q. The brass scale of a barometer gives a reading at zero degree celsius. The Barometer reads 75 cm at 27 degree Celsius. What is the correct atmospheric pressure at 27 degree Celsius. The coefficient of linear expansion Alpha of brass is 2.0 × 10 ^-5 /°c

Q. Brass scale of a Barometer gives correct reading at

0^{\circ} C .

coefficient of linear expansion of brass is

18 \times 10^{- 6} /^{- 6} C .

If the barometer reads

76 c m

20^{\circ} C,

the correct reading is

(γ_{H g} = 18 \times 10^{- 5} / 0 C)

Q. A barometer with a brass scale correct at

0^{o} C

reads

70 c m

of mercury on a day when the air temperature is

40^{o} C

. the correct reading at

0^{o} C

is (Coefficient of real expansion of mercury, is

0.00018 /^{o} C

and the coefficient of linear expansion of brass is

0.000018 /^{o} C

Q. A barometer having a metallic scale reads a height

H_{0}

at temperature

θ^{\circ} C

. The true scale is calibrated at

0^{\circ} C

. If

α

is the coefficient of linear expansion of the metal and

γ

the coefficient of cubical expansion of mercury, the correct pressure

H_{c o r r}

is:

A barometer reads 75.0 cm on a steel scale. The room temperature is $30^{\circ} C$ . The scale is correctly graduated for $0^{\circ} C$ . The coefficient of linear expansion of steel is $α$ = $1.2 \times 10^{- 5} /^{\circ} C$ and the coefficient of volume expansion of mercury is $γ$ = $1.8 \times 10^{- 4} /^{\circ} C$ . Find the correct atmospheric pressure.

Join BYJU'S Learning Program

The brass scale of a barometer gives correct reading at 0oC. The barometer reads 75cm at 27oC. what is the correct atmospheric pressure at 27oC. Tne coefficient of linear expansion α of brass is 2.0×10−5degree/celcius

Lo = 75cmα = 20×10−6degree−celciusΔT= 27 – 0 = 27 degree-celsiusL = ?# Formula-We'll use the formula for the coefficient of linear expansionL=Lo(1+aΔT)L=75(1+20×10−6×27)L=75(1+0.00054)L=75×1.00054L=75.0405cmAtmospheric pressure at 270 is 75.0405 cm of brass.

The brass scale of a barometer gives correct reading at $0^{o} C$ . The barometer reads $75 c m$ at $27^{o} C$ . what is the correct atmospheric pressure at $27^{o} C$ . Tne coefficient of linear expansion $α$ of brass is $2.0 \times 10^{- 5}$ degree/celcius