Tag: application of various thermometric scales

Questions Related to application of various thermometric scales

 The value of absolute zero temperature in Fahrenheit scale is 

  1. $ - 273^\circ F$

  2. $ - 32^\circ F$

  3. $ - 460^\circ F$

  4. $ - 132^\circ F$


Correct Option: C
Explanation:

Absolute temperature in Celsius is $-273.15{{\,}^{o}}C$

$ F=\dfrac{9}{5}C+32 $

$ F=\dfrac{9}{5}\times (-273.15)+32=-459.67{{\,}^{o}}F $

$ F\cong -460{{\,}^{o}}F $

Hence, absolute temperature in Fahrenheit

A piece of lead falls from height of $100m$ on a fixed non-conducting slab which brings it to rest. if the specific heat of lead is $30.6 cal/kg ^ \circ C $ the increase in temperature of the slab immediately after collision is  

  1. ${6.72^ \circ }C$

  2. ${7.62^ \circ }C$

  3. ${5.62^ \circ }C$

  4. ${8.72^ \circ }C$


Correct Option: B

A physicist says "a body contains $10\ joule$ heat" but a physics learner says "this statement is correct only when the body is in liquid state". Mark correct option or options :

  1. physicist statement is correct

  2. physics learner's statement is correct

  3. both statements are correct

  4. both statements are wrong


Correct Option: D

Two identical rods of a mental are welded in series then 20 cal of heat flows through them in  4 minute. If the rods are welded in parallel then same amount of heat will flow in 

  1. 1 minute

  2. 2 minute

  3. 4 minute

  4. 15 minute


Correct Option: A
Explanation:

$dq/dt = [(AK)/2x][T2-T1] = 20/4 = 5.$

 $Therefore ( AK/x)(T2-T1) = 10$

When they are one above the other,

$dq/dt = 2Ak/x][T2-T1] =20/t$

Therefore$t = 2\times10  = 20/t$

Therefore$ t = 1 min$

A liter of air at $20^oC$ is heated until both the pressure and the volume are tripled, what is the tempertare then.

  1. $2637^oK$

  2. $927^oK$

  3. $200^oK$

  4. $977^oK$


Correct Option: A
Explanation:

Applying the formula

$PV=nRT$
$\dfrac { { P } _{ 1 } }{ { V } _{ 1 } } =\dfrac { { P } _{ 2 } }{ { V } _{ 2 } } =\dfrac { { T } _{ 1 } }{ { T } _{ 2 } } $    [$R$ is constant]
Let ${ P } _{ 1 }=P$  and ${ V } _{ 1 }=V$
As given ${ P } _{ 2 }=3P$   ${ V } _{ 2 }=3V$
${ T } _{ 1 }={ 20 }^{ 0 }C=20+2+3=293$
${ T } _{ 2 }=?$
$\dfrac { PV }{ 3P\times 3V } =\dfrac { 293 }{ { T } _{ 2 } } $
$\dfrac { 1 }{ 9 } =\dfrac { 293 }{ { T } _{ 2 } } $
${ T } _{ 2 }=293\times 9=2637$
$\therefore$    New temperature $=2637$.