The reading of a barometer containing some air above the mercury column is 73cm while that of a correct one is 76cm. If the tube of the faulty barometer is pushed down into mercury until volume of air in it is reduced to half, the reading shown by it will be:

the height of mercury in a fauilty barometer is 75 cm and the tube above mercury is 10 cm long. The correct barometer reading is 76 cm. when the faulty barometer reads 74 cm, find the true barometer reading .

The reading in a barometer changes from 75 cmHg to 25 cmHg when 10 cm^3 of air of atmospheric pressure is introduced in the vaccum space of the barometer tube. What is the volume of air in the tube?

If the length of the mercury column in a mercury barometer is 76 cm, what is the equivalent height of the water column ?

A barometer is an instrument that is used for the measurement of pressure The construction of the barometer is as follows: A thin narrow calibrated capillary tube is filled to the brim with a liquid such as mercury and is inverted into a through filled with the same fluid Now depending on the external atmospheric pressure the level of the inside capillary comes to rest, then the net forces on the column should be balanced Applying force balance we get P_(atm)xxA=mxxg (A is the cross-sectional area of the capillary tube) if rho is the density of the fluid, then m=rhoxxgxxh (h is the height to which mercury has risen in the capillary) Hence P_(atm)xxA=(rhoxxgxxh)xxA or P_(atm)=rhogh Faulty Barometer: An ideal barometer will show a correct reading only if the space above the mercury column is vacuum but in case if some gas column is trapped in the space above the mercury column then the barometer is classified as a faulty barometer. The reading of such a barometer will be less than the true pressure For such a faulty barometer P_(0)A=mg+P_(gas)A P_(0)=rhohg+P_(gas) or rhogh=P_(0)-P_(gas) A tube closed at one end is dipped in mercury as shown in figure such that the closed surface coincides with the mercury level in the container By how much length of the tube should be extended such that the level of Hg in the tube is 5 cm below the mercury level inside the container? (Assume temperature remains constant)

A barometer tube contains a mixture of air and saturated water vopour in the space above the mercury column. It reads 70cm when the actual atmospheric pressure is 76cm of mercury. The saturation vapour pressure at roon tempature is1.0 cm of mercury, The tube is now lowered in the reservoir till the space above the mercury cloumn is reduced to half its origina volume. Find the reading of the barometer. Assume that the temperature remains constant.

A barometer tube contains a mixture of air and saturated water vopour in the space above the mercury column. It reads 70cm when the actual atmospheric pressure is 76cm of mercury. The saturation vapour pressure at roon tempature is1.0 cm of mercury, The tube is now lowered in the reservoir till the space above the mercury cloumn is reduced to half its origina volume. Find the reading of the barometer. Assume that the temperature remains constant.

A barometer tube of length 90 cm contains some air above mercury. The reading of the mercury level is 74.8 cm when the atmospheric pressure is 76 cm and temperature is 30^@C . If the reading is observed to be 75.4 cm on some another day when temperature is 10^@C , then what will be true pressure?