Tag: introduction to temperature

Questions Related to introduction to temperature

We cannot use mercury thermometer at low temperatures because:

physics heat - measurement application of various thermometric scales different types of thermometers measuring temperature introduction to temperature

  1. Glass might break down at low temperature.

  2. Heat does not flow from the body whose measurement we are taking with the thermometer.

  3. At low temperatures mercury becomes transparent and it becomes difficult to take the readings.

  4. Mercury freezes at low temperatures.

Show answer
Correct Option: D
Explanation:

Mercury, which is used as a thermometric liquid, has the following characteristic properties:

1. Mercury has a high boiling point of about $357^{\circ}$C and therefore can be used to measure temperatures as high as $357^{\circ}$C.

2. Mercury has a freezing point of about $-39^{\circ}$C and hence it is suitable in thermometers to record low temperatures (although not very low temperatures).

3. Mercury is opaque and has a shining silvery colour of its own, making it clearly visible in the capillary tube of a thermometer. 


4. Mercury needs very little heat to expand and so it can easily measure the temperature of a body without causing a decrease in the body's temperature.

5. Mercury does not stick to the side of the glass capillary tube of a thermometer. Therefore, it allows accurate temperature measurement.

6. Mercury is a good conductor of heat.

7. Mercury is relatively expensive.

Mercury is commonly used as a thermometric fluid rather than water because

physics heat - measurement application of various thermometric scales different types of thermometers measuring temperature introduction to temperature

  1. specific heat of mercury is less than water

  2. specific heat of mercury is more than water

  3. mercury has greater visibility than water

  4. density of mercury is more than the water

Show answer
Correct Option: C
Explanation:
Mercury is commonly used as a thermometric fluid rather than water because mercury has greater visibility than water
Mercury has high melting and boiling points making it a liquid over a broad range of temperature.
Since it is a metal, it has a stable coefficient of expansion hence it expands uniformly and noticeably for a slight change of temperature.
Mercury is a non sticky viscous metal and hence it makes a clear meniscus, helpful in readings.
Mercury will not expand when it solidifies hence it doesn’t break the glass tube of the thermometer.

Compared to other liquids, why is mercury preferred as a barometric fluid?

physics heat - measurement application of various thermometric scales different types of thermometers measuring temperature introduction to temperature

  1. Height of mercury barometer is smaller so it is more convenient to handle

  2. Mercury does not stick to the glass surface of barometric tube

  3. Mercury shines so it is easier to take the observations

  4. Coefficient of expansion of mercury is less than other liquids

Show answer
Correct Option: A,B

A thermometer is gradated in millimeters . It registers -3 mm when the bulb of themometer is a pure melting ice  and 22 mm when the thermometer is in stem at a pressure of 1 atmosphere. The temperature in $^{ \circ  }C$  when the thermometer registers 13 mm is 

physics heat - measurement application of various thermometric scales different types of thermometers measuring temperature introduction to temperature

  1. $\frac { 13 }{ 25 } \times 100$

  2. $\dfrac { 16 }{ 25 } \times 100$

  3. $\dfrac { 13 }{ 22 } \times 100$

  4. $\dfrac { 16 }{ 22 } \times 100$

Show answer
Correct Option: A

A________is used to measure temperature

physics heat - measurement application of various thermometric scales different types of thermometers measuring temperature introduction to temperature

  1. Thermometer

  2. Barometer

  3. Manometer

  4. None of these

Show answer
Correct Option: A
Explanation:

A thermometer is a device that measures temperature or a temperature gradient. A thermometer has two important elements: (1) a temperature sensor (e.g. the bulb of a mercury-in-glass thermometer or the digital sensor in an infrared thermometer) in which some change occurs with a change in temperature, and (2) some means of converting this change into a numerical value (e.g. the visible scale that is marked on a mercury-in-glass thermometer or the digital readout on an infrared model). Thermometers are widely used in industry to monitor processes, in meteorology, in medicine, and in scientific research

Water is better thermometric liquid

physics heat - measurement application of various thermometric scales different types of thermometers measuring temperature introduction to temperature

  1. True

  2. False

Show answer
Correct Option: B
Explanation:

The above statement is false.

Water can't be used as thermometric liquid as:
(i) It sticks to the glass
(ii) It is transparent, and hence difficult to read its level through 
(iii) It is volatile and hence vapors apply pressure on the surface thereby affecting reading
(iv) It is a poor conductor of heat.
(v) its expansion is not uniform.
(vi) It freezes at 0°C and boils at 100°C and hence range is not very wide.

State whether given statement is True or False
Thermometer measures the heat energy in a body

physics heat - measurement application of various thermometric scales different types of thermometers measuring temperature introduction to temperature

  1. True

  2. False

Show answer
Correct Option: B
Explanation:

A thermometer is a tool that measures temperature — how hot or cold something is.Made up of thermo (heat) and meter (measuring device), the meaning of the word thermometer is pretty straightforward. Thermometers measure temperatures in degrees, according to either the Celsius or Fahrenheit system.

Thermometer measures the temperature of body

State whether true or false.
Thermometer is an instrument used for measuring the temperature of a body

physics heat - measurement application of various thermometric scales different types of thermometers measuring temperature introduction to temperature

  1. True

  2. False

Show answer
Correct Option: A
Explanation:
A Thermometer is a device. which measures the temperature of the body it is brought in contact with.
Hence, OPTION : A (true).

Name the device for detecting and measuring small amount of thermal energy.

physics heat - measurement application of various thermometric scales different types of thermometers measuring temperature introduction to temperature

  1. Pyranometer

  2. Pyrometer

  3. Barrater

  4. Bolometer

Show answer
Correct Option: D

State whether true or false :
A gas thermometer measures temperature with the variation in pressure or volume of a gas.

physics heat - measurement application of various thermometric scales different types of thermometers measuring temperature introduction to temperature

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

A gas thermometer measures temperature by the variation in volume or pressure of a gas.This thermometer functions by Charles's Law. Charles's Law states that when the temperature of a gas increases, so does the volume.

Using Charles's Law, the temperature can be measured by knowing the volume of gas at a certain temperature by using the formula, written below. Translating it to the correct levels of the device that is holding the gas. This works on the same principle as mercury thermometers.

${\displaystyle V\propto T\,},$
or

${\displaystyle {\dfrac {V}{T}}=k} $
T is the temperature.

V is the volume.