Tag: measuring temperature

Questions Related to measuring temperature

During burning of a candle, different zones of combustion in the flame are listed below:

A. outermost zone
B. innermost zone
C. middle zone
The correct order of temperature of zones is :

  1. $A > B > C$

  2. $C > B > A$

  3. $B > C > A$

  4. $A > C > B$


Correct Option: D
Explanation:

The correct order of temperature of zones of candle flames is -
Outermost zone > Middle zone > innermost zone.
Because outerzone will have the highest temperature and inner zone will have the least temperature.

At what temperature is the Fahrenheit scale reading equal to twice of Celsius ?

  1. $ 40^0C $

  2. $ 160^0C $

  3. $ 80^0C $

  4. $ 100^0C $


Correct Option: B
Explanation:

We know the relation between Fahrenheit scale and degree celsius,


$\dfrac{C-0}{100}=\dfrac{F-32}{180}$

Given,

$F=2C$

Then,

$\dfrac{C}{100}=\dfrac{2C-32}{180}$

$\dfrac{C}{100}=\dfrac{C-16}{90}$

$\implies 9C=10C-160$

$\implies C=160^0C$

A man wishes to fit an aluminium ring on steel rod of 1 cm diameter and found it is 0.01 cm smaller in diameter. How much should the on temperature be raised before it just slips on the
$(\alpha _A = 25 \times 10^{-6}/^oC;$ $10 \times 10^{-6}/^oC)$

  1. $40^oC$

  2. $50^oC$

  3. $25^oC$

  4. $60^oC$


Correct Option: A
Explanation:

${l _2} = {l _1}\left( {1 + {\alpha _A}\Delta T} \right)$

${l _2} = {l _1} + {l _1}{\alpha _A}\Delta T$

$\displaystyle {{{l _2} - {l _1}} \over {{l _1}}} = {\alpha _A}\Delta T$

$\displaystyle {{0.01 \times {{10}^{ - 2}}} \over {1 \times {{10}^{ - 2}} \times 25 \times {{10}^{ - 6}}}} = \Delta T$

$\Delta T = {40^0}C$

Which of the following physical quantities is measured in calories ? 

  1. Heat energy

  2. Force

  3. Momentum

  4. Temperature


Correct Option: A
Explanation:

1 calorie: The amount of energy required to warm $1\ g$ of air-free water from $14.5^oC\ to\ 15.5^oC$ at a constant pressure of $101.325\ kPa$ $(1 atm)$

Name the S.I. unit of heat.

  1. Joule

  2. Kelvin

  3. Degree centigrade

  4. All of the above


Correct Option: A
Explanation:

Answer is (A).

It has the same unit as of energy that's Joule.

State the S.I. unit of heat capacity.

  1. $ J^{-1}K^{-1}$

  2. $ JK^{-2}$

  3. $ JK$

  4. $ JK^{-1}$


Correct Option: D
Explanation:

The S.T. unit of heat capacity is heat required per degree rise in temperature. So it is $JK^{-1}$

1 cal = _________

  1. 10 joules

  2. 4.18 joules

  3. 4.18 dynes

  4. None of these


Correct Option: B
Explanation:

1 cal = 4.18 joules

C.G.S unit of heat is calorie.
S.I. unit of heat is joule.

The SI unit of heat is:

  1. calorie

  2. joule

  3. dyne

  4. newton


Correct Option: B

Therm is a unit of

  1. heat

  2. temperature

  3. thermometry

  4. mass


Correct Option: A
Explanation:

The therm (symbol, thm) is a non-SI unit of heat energy equal to100000 British thermal units (Btu). It is approximately the energy equivalent of burning 100 cubic feet (2.83 cubic metres) – often referred to as 1 CCF – of natural gas.

For a gm molecule of an ideal gas

  1. ${PV}/{T} = 2$ calories

  2. ${PV}/{T} = 4.2$ calories

  3. ${PV}/{T} = 4.31$ calories

  4. ${PV}/{T} = 4.2 \times {10}^{7}$ ergs


Correct Option: B