Courses
Courses for Kids
Free study material
Offline Centres
More
Store Icon
Store
seo-qna
SearchIcon
banner

One Torr is equal to
(A) 1 cm of Hg
(B) 1 atm pressure
(C) 1 mm of Hg
(D) 1 Nm2

Answer
VerifiedVerified
495.6k+ views
like imagedislike image
Hint:Torr is a unit of pressure named after the scientist Evangelista Torricelli, who discovered a barometer's principle. Torr was named in honor of the inventor of the barometer, Evangelista Torricelli. Torr is used to represent minimal pressure values.

Complete step by step answer:
Torr is a unit of pressure. It is defined as precisely 1760of a standard atmosphere.
It can be written in the formula as,
1torr=1760×Patm......(I)
Here Patm is the standard atmospheric pressure.
Since we know that 1Patm=760mmHg and we will substitute this in equation (I) and we get,
1torr=760mmHg760=1mmHg
Therefore option (C) is correct.
We will now convert 1 mm Hg into cm of Hg.
1torr==1mmHg×101cmHg1mmHg=0.1cmHg
Therefore, option (A) is wrong.
We know that 1 torr is defined as 1760of a standard atmosphere as mentioned earlier that is,
1torr=1760×Patm
Therefore, option (B) is wrong.
We know that 1Patm=101325N/m2, and we will substitute this value in equation (I) and we will get,
1torr=101325N/m2760=133.322N/m2
Therefore, option (D) is also wrong.
Therefore, the correct option is 1torr=1mmHg, and the right option is (C).

Additional information:
 Pressure (p) is the force applied perpendicular to an object's surface per unit area. Some other units of pressure are below. The bar (denoted by the bar), defined as 100 kPa precisely. The atmosphere (indicated by atm), defined as 101.325 kPa.

Note: Earlier, one Torr was intended to be the same as one "millimeter of mercury," but subsequent research of the two units made them slightly different. It is one of the measuring units in a high vacuum. Some devices, such as Electron beam machining, operate at minimal pressures near to vacuum, and their Torr as a pressure unit is used for measurement.
Latest Vedantu courses for you
Grade 11 Science PCM | CBSE | SCHOOL | English
CBSE (2025-26)
calendar iconAcademic year 2025-26
language iconENGLISH
book iconUnlimited access till final school exam
tick
School Full course for CBSE students
PhysicsPhysics
ChemistryChemistry
MathsMaths
₹41,848 per year
Select and buy