Tag: physics

Questions Related to physics

Two thermometers, one calibrated in celsius and the other in fahrenheit scale, are used to measure the temperature of the same object. if the readings are in $ ^0C $ and $ ^0F $ then :

physics heat - measurement thermometers application of various thermometric scales different types of thermometers

  1. C>F

  2. F

  3. F=C

  4. $ F \gtreqless C $

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Correct Option: C

At low temperatures ................. type of thermometer is used.

physics heat - measurement thermometers application of various thermometric scales different types of thermometers

  1. mercury thermometer

  2. water thermometer

  3. alcohol thermometer

  4. thermometers cannot be used

Show answer
Correct Option: C
Explanation:

Alcohol thermometer.
Alcohol expands uniformly.

It has a low freezing point (-115 degree centigrade) therefore it is very suitable for the place where the temperature gets very low.
It is an easily available cheap liquid, which is safe to use.
Alcohol is cheaper than mercury, and if you break the thermometer, it is not toxic.

The boiling point of mercury is 367$^o$C. A mercury thermometer can be used to measure a temperature of 500$^o$C;

physics heat - measurement thermometers application of various thermometric scales different types of thermometers

  1. by filling the space above mercury with oxygen at high pressure

  2. by filling the space above mercury with nitrogen at low pressure

  3. by filling the space above mercury with nitrogen at high pressure

  4. by keeping the space above mercury as vacuum

Show answer
Correct Option: C
Explanation:

The mercury thermometer can be used above its boiling point by filling up the space above mercury with nitrogen at high pressure because as pressure increases, boiling point also increases.

Boiling water can be measured by 

physics heat - measurement thermometers application of various thermometric scales different types of thermometers

  1. Clinical thermometer

  2. Laboratory thermometer

  3. Both may be used conveniently

  4. Both of them can not be used

Show answer
Correct Option: B
Explanation:
Laboratory thermometers are used to measure temperatures or temperature changes with a high degree of precision. That's why these are mainly used in laboratories. For exp : To measure boiling points of solutions, water etc. They are made up of glass and strength through thermal tempering or annealing. Types : liquid-in-glass, bimetallic strip, infrared based thermometer.
Hence, the answer is Laboratory thermometer.

A clinical thermometer reads temperature from

physics heat - measurement thermometers application of various thermometric scales different types of thermometers

  1. $35^oC to \ 42^oC$

  2. $0^oC to \ 100^oC$

  3. $25^oC to \ 42^oC$

  4. $35^oC to \ 62^oC$

Show answer
Correct Option: A
Explanation:
A clinical thermometer is a thermometer used to measure human body temperature. Most made in $20th$ century are mercury-in-glass thermometers. They are very sensitive as mercury level rises very fast with small variation in temperature most of these thermometers shows Celsius and Fahrenheit ( medical thermometer ) scales and runs from $35°C$ to $42°C.$
Hence, the answer is $35°C$ to $42°C.$

The clinical thermometer is designed to measure the temperature of

physics heat - measurement thermometers application of various thermometric scales different types of thermometers

  1. Human body

  2. Bodies kept in refrigerators

  3. Room temperature

  4. boiling water

Show answer
Correct Option: A
Explanation:
A Clinical thermometer is a thermometer used to measure human body temperature. Most made in $20th$ century are mercury-in-glass thermometers. They are very fast with small variation in temperature. Most of these thermometers shows Celsius and Fahrenheit ( medical thermometer ) scales and runs from $35°C$ to $42°C.$
Hence, the answer is Human body.

What is the use of kink near the bulb in clinical thermometer

physics heat - measurement thermometers application of various thermometric scales different types of thermometers

  1. It prevents the level of the mercury from falling when taken out of the mouth

  2. It allows the level of the mercury to fall when taken out of the mouth

  3. It allows the level of the mercury to rise when taken out of the mouth

  4. It prevents the level of the mercury from rising when taken out of the mouth

Show answer
Correct Option: A,B
Explanation:
Since, in clinical thermometer, mercury is used and level of mercury rises very rapidly with small variation in temperature that's why thermometers provided with kink near the bulb so it prevents the level of mercury from falling when taken out of mouth.
Hence, the answers are it prevent the level of the mercury from falling when taken out of the mouth, it allows the level of the mercury to fall when taken out of the mouth.

When a mercury thermometer is inserted in a pot of hot water and the reading is recorded , what temperature is being 

physics heat - measurement thermometers application of various thermometric scales different types of thermometers

  1. Average temperature of water and surroundings

  2. Average temperature of thermometer

  3. Average temperature of water and thermometer

  4. Temperature difference between water and surroundings

Show answer
Correct Option: B
Explanation:

In this process, thermal equilibrium will eventually be reached after inserting the thermometer in hot pot. Hence heat is transferred from the water to the thermometer. 

The steam point and the ice point of a mercury thermometer are marked $80^0$ and $20^0.$  what will be the temperature in centigrade mercury scale when this thermometer reads $32^0$

physics heat - measurement thermometers application of various thermometric scales different types of thermometers

  1. $20 ^ { 0 } \mathrm { C }$

  2. $5 ^ { 0 } \mathrm { C }$

  3. $10 ^ { 0 } \mathrm { C }$

  4. $26 ^ { 0 } \mathrm { C }$

Show answer
Correct Option: A
Explanation:

$(x-20)/(80-20) =(C-0)/(100-0)$
$(x-20)/60=(C-0)/100$

Now, given question$,$
$x=32 $
then$ ,$
$(32-20)/60=(C-0)/100$
$12/60=C/100$
$C=20^0$
hence in centigrade thermometer $20^0C$
Hence,
option $(A)$ is correct answer.

Mercury is often used in clinical thermometers. Which one of the following properties of mercury is not a reason for this ?

physics heat - measurement thermometers application of various thermometric scales different types of thermometers

  1. The coefficient of the thermal expansion is large

  2. It is shiny

  3. It is a liquid at room temperature

  4. It has high density.

Show answer
Correct Option: D
Explanation:
Mercury is used in thermometer as it has high coefficient of  expansion so even the highest change can be observed, it is spiny So you can see the level of mercury clearly and it is liquid for a wide range of temperature.
Hence, OPTION : D (density).