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Multiple choice physics temperature and heat application of various thermometric scales different types of thermometers measuring temperature

If two temperatures differ by 25 degrees on Celsius scale, the difference of temperature on Fahrenheit scale is 

  1. $65^{\circ}$

  2. $45^{\circ}$

  3. $38^{\circ}$

  4. $25^{\circ}$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Each Celsius degree equals 5/9ths of a Fahrenheit degree. 

Each Fahrenheit degree equals 9/5ths of a Celsius degree. 

A 25 degree difference in Celsius would be 25 x 9/5 = 45 degrees Fahrenheit.

Multiple choice physics temperature and heat application of various thermometric scales different types of thermometers measuring temperature

A Centigrade and Fahrenheit thermometers are dipped in boiling water. The water temperature is lowered unit the Fahrenheit thermometre registers a temperature of $140^o$. The fall of temperature as registered by the Centigrade thermometre is :

  1. $80^o$C

  2. $40^o$C

  3. $50^o$C

  4. $90^o$C
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Boiling point is 100C or 212F. The temperature dropped from 212F to 140F, a change of 72F. The conversion factor is 5/9. Change in C = (5/9) * 72 = 5 * 8 = 40C.

Multiple choice physics temperature and heat application of various thermometric scales different types of thermometers measuring temperature

On a new scale of temperature (which is linear) and called the W scale, the freezing and boiling points of water are $39^o$W and $239^o$W respectively. What will be the temperature on the new scale, corresponding to a temperature of $39^o$C on the Celsius scale ?

  1. $78^o$W

  2. $117^o$W

  3. $200^o$W

  4. $139^o$W
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The scale is linear: W = m * C + c. 0C = 39W, 100C = 239W. Slope m = (239-39)/100 = 2. W = 2 * C + 39. For C = 39, W = 2 * 39 + 39 = 78 + 39 = 117.

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

People boil water as safe measure to drink because:

  1. Boiled water is tasty

  2. Boiled water is more powerful

  3. Heating water is fashionable

  4. Excessive heat kills the microorganisms present in the water
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

People boil water as safe measure to drink because excessive heating kills the microorganisms present in the water and becomes safe to drink it.

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

The most commonly used thermometric substance is

  1. water

  2. alcohol

  3. mercury

  4. steam
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Mercury is the only one in liquid state at room temperature. It's used in thermometers because it has high coefficient of expansion. Hence, the slightest change in temperature is notable when it's used in a thermometer. It also has a high boiling point which makes it very suitable to measure higher temperatures, and it doesn't stick to glass.

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

State whether given statement is True or False
The upper standard point of a thermometer is 273 K

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The lower fixed point, or ice point, is the temperature of pure melting ice at normal atmospheric pressure. The upper fixed point, or steam point, is the temperature of pure boiling water at normal atmospheric pressure.

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

A barometer with a brass scale correct at $0^oC$ reads $70\ cm$ of mercury on a day when the air temperature is $40^oC$. the correct reading at $0^oC$ is (Coefficient of real expansion of mercury, is $0.00018/^oC$ and the coefficient of linear expansion of brass is $0.000018/^oC$.

  1. $60.5\ cm$

  2. $69.5\ cm$

  3. $20.5\ cm$

  4. $50.00\ cm$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

If the correct heading of barometer at $0^oC$ is $70\ cm$ then the at $40^oC,$ the reading will show,

$L=70(1+\alpha _1\Delta T)$    $[\alpha$ ,of Brass , $\Delta T=40\ k]$
similarly , mercury expands to $70\ cm$ from initial length $Lo$
$\Rightarrow L=Lo(1+\alpha _2\Delta T)$   ($\alpha _2:$ mercury)
It gives :-
$Lo=\dfrac{70(1+\alpha _2\Delta T)}{(L+\alpha _2\Delta T)}=\dfrac{70(1+1.8\times Lo^{-5}\times 40)}{(1+1.8\times 10^{-4}\times40)}$
$Lo=69.55\ cm$