Tag: physics

Questions Related to physics

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

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

  1. $65^{\circ}$

  2. $45^{\circ}$

  3. $38^{\circ}$

  4. $25^{\circ}$

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Correct Option: B
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.

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 :

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

  1. $80^o$C

  2. $40^o$C

  3. $50^o$C

  4. $90^o$C

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Correct Option: B

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 ?

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

  1. $78^o$W

  2. $117^o$W

  3. $200^o$W

  4. $139^o$W

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Correct Option: B

The range of a clinical thermometer is

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

  1. 0-100$^0$C

  2. 32-214$^0$F

  3. 0-1273$^0$C

  4. 35-42$^0$C

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Correct Option: D
Explanation:

A clinical thermometer is used to measure the body temperature which normally remains between $35^{\circ}$C and $42^{\circ}$C.


People boil water as safe measure to drink because:

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

  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

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Correct Option: D
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.

At low temperatures ________  type of thermometer is used.

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

  1. mercury thermometer

  2. water thermometer

  3. alcohol thermometer

  4. thermometers cannot be used

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Correct Option: C
Explanation:

Alcohol has a low freezing point.

The most commonly used thermometric substance is

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

  1. water

  2. alcohol

  3. mercury

  4. steam

Show answer
Correct Option: C
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.

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

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 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.

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 $0.000018/^oC$.

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

  1. $60.5\ cm$

  2. $69.5\ cm$

  3. $20.5\ cm$

  4. $50.00\ cm$

Show answer
Correct Option: B
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 :-
$Lo=\dfrac{70(1+\alpha _2\Delta T)}{(L+\alpha _2\Delta T)}=\dfrac{70(1+1.8\times Lo^{-5}\times 40)}{(1+1.8\times 10^{-4}\times40)}$
$Lo=69.55\ cm$

A Fahrenheit thermometer registers $107^{o}F$ while a faulty Celsius thermometer registers $42^{o}C$. Find the error in the later

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

  1. $0.37^{o}$

  2. $0.87^{o}$

  3. $0.67^{o}$

  4. $48$

Show answer
Correct Option: C