JEE Main & Advanced Physics Transmission of Heat Question Bank

done Radiation Newton's Law of Cooling Total Questions - 37

• question_answer1)
  Hot water cools from \[{{60}^{o}}C\] to \[{{50}^{o}}C\] in the first 10 minutes and to \[A\] in the next 10 minutes. The temperature of the surrounding is                     [MP PET 1993]
  A)
             \[{{5}^{o}}C\]                       done clear
  B)
             \[{{10}^{o}}C\] done clear
  C)
             \[{{15}^{o}}C\]                     done clear
  D)
             \[{{20}^{o}}C\] done clear
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• question_answer2)
  A bucket full of hot water cools from \[{{75}^{o}}C\] to \[{{70}^{0}}C\] in time \[{{T}_{1}}\], from \[{{70}^{o}}C\] to \[{{65}^{o}}C\] in time \[{{T}_{2}}\] and from \[{{65}^{o}}C\] to \[{{60}^{o}}C\] in time \[{{T}_{3}}\], then              [NCERT 1980; MP PET 1989; CBSE PMT 1995; KCET 2003; MH CET 1999]
  A)
             \[{{T}_{1}}={{T}_{2}}={{T}_{3}}\]                                      done clear
  B)
             \[{{T}_{1}}>{{T}_{2}}>{{T}_{3}}\] done clear
  C)
             \[{{T}_{1}}<{{T}_{2}}<{{T}_{3}}\]                                      done clear
  D)
             \[{{T}_{1}}>{{T}_{2}}<{{T}_{3}}\] done clear
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• question_answer3)
  Consider two hot bodies \[{{B}_{1}}\] and \[{{B}_{2}}\] which have temperatures \[{{100}^{o}}C\] and \[{{80}^{o}}C\] respectively at \[t=0\]. The temperature of the surroundings is \[{{40}^{o}}C\]. The ratio of the respective rates of cooling \[{{R}_{1}}\] and \[{{R}_{2}}\] of these two bodies at \[t=0\] will be                                         [MP PET 1990]
  A)
             \[{{R}_{1}}:{{R}_{2}}=3:2\]      done clear
  B)
             \[{{R}_{1}}:{{R}_{2}}=5:4\] done clear
  C)
             \[{{R}_{1}}:{{R}_{2}}=2:3\]      done clear
  D)
             \[{{R}_{1}}:{{R}_{2}}=4:5\] done clear
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• question_answer4)
  Newton's law of cooling is a special case of
  A)
             Stefan's law                           done clear
  B)
             Kirchhoff's law done clear
  C)
             Wien's law                             done clear
  D)
             Planck's law done clear
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• question_answer5)
  Equal masses of two liquids are filled in two similar calorimeters. The rate of cooling will [MP PMT 1987]
  A)
             Depend on the nature of the liquids done clear
  B)
             Depend on the specific heats of liquids done clear
  C)
             Be same for both the liquids done clear
  D)
             Depend on the mass of the liquids done clear
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• question_answer6)
  In Newton's experiment of cooling, the water equivalent of two similar calorimeters is 10 gm each. They are filled with 350 gm of water and 300 gm of a liquid (equal volumes) separately. The time taken by water and liquid to cool from \[{{70}^{o}}C\] to \[{{60}^{o}}C\] is 3 min and 95 sec respectively. The specific heat of the liquid will be
  A)
             0.3 Cal/gm ´°C                     done clear
  B)
             0.5 Cal/gm ´°C done clear
  C)
             0.6 Cal/gm ´°C                     done clear
  D)
             0.8 Cal/gm ´°C done clear
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• question_answer7)
  Newton's law of cooling is used in laboratory for the determination of the           [CPMT 1973; CPMT 2002]
  A)
             Specific heat of the gases       done clear
  B)
             The latent heat of gases done clear
  C)
             Specific heat of liquids      done clear
  D)
             Latent heat of liquids done clear
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• question_answer8)
    A body cools from \[{{60}^{o}}C\] to \[{{50}^{o}}C\] in 10 minutes when kept in air at \[{{30}^{o}}C\]. In the next 10 minutes its temperature will be                                                                 [MP PET 1994]
  A)
             Below \[{{40}^{o}}C\]       done clear
  B)
             \[{{40}^{o}}C\] done clear
  C)
             Above \[{{40}^{o}}C\]       done clear
  D)
             Cannot be predicted done clear
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• question_answer9)
  Liquid is filled in a vessel which is kept in a room with temperature \[{{20}^{o}}C\]. When the temperature of the liquid is \[{{80}^{o}}C\], then it loses heat at the rate of \[60\ cal/\sec \]. What will be the rate of loss of heat when the temperature of the liquid is \[{{40}^{o}}C\]                                                         [MP PMT 1994]
  A)
             \[180\ cal/\sec \]                 done clear
  B)
             \[40\ cal/\sec \] done clear
  C)
             \[30\ cal/\sec \]                   done clear
  D)
             \[20\ cal/\sec \] done clear
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• question_answer10)
  Which of the following statements is true/correct [Manipal MEE 1995
  A)
                     During clear nights, the temperature rises steadily upward near the ground level done clear
  B)
             Newton's law of cooling, an approximate form of Stefan's law, is valid only for natural convection done clear
  C)
             The total energy emitted by a black body per unit time per unit area is proportional to the square of its temperature in the Kelvin scale done clear
  D)
             Two spheres of the same material have radii \[1m\] and \[{{S}_{1}}\] and temperatures 4000 K and 2000 K respectively. The energy radiated per second by the first sphere is greater than that radiated per second by the second sphere done clear
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• question_answer11)
  A body takes 4 minutes to cool from \[{{100}^{o}}C\] to \[{{70}^{o}}C\]. To cool from \[{{70}^{o}}C\] to \[{{40}^{o}}C\] it will take (room temperature is \[{{15}^{o}}C\])                                              [MP PET 1995]
  A)
             7 minutes                               done clear
  B)
             6 minutes done clear
  C)
             5 minutes                               done clear
  D)
             4 minutes done clear
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• question_answer12)
     A cup of tea cools from \[{{80}^{0}}C\] to \[{{60}^{o}}C\] in one minute. The ambient temperature is \[{{30}^{o}}C\]. In cooling from \[{{60}^{o}}C\] to \[{{50}^{o}}C\] it will take         [MP PMT 1995; UPSEAT 2000;  MH CET 2002]
  A)
             \[30\ \sec onds\]                done clear
  B)
             \[60\ \sec onds\] done clear
  C)
             \[90\ \sec onds\]                done clear
  D)
             \[50\ \sec onds\] done clear
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• question_answer13)
   A liquid cools down from \[{{70}^{o}}C\] to \[{{60}^{o}}C\] in 5 minutes. The time taken to cool it from \[{{60}^{o}}C\] to \[{{50}^{o}}C\] will be [MP PET 1992, 2000; MP PMT 1996]
  A)
             5 minutes                               done clear
  B)
             Lesser than 5 minutes done clear
  C)
             Greater than 5 minutes    done clear
  D)
             Lesser or greater than 5 minutes depending upon the density of the liquid done clear
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• question_answer14)
  If a metallic sphere gets cooled from \[{{62}^{o}}C\] to \[{{50}^{o}}C\] in \[{{40}^{o}}C\]and in the next \[10\ \min utes\]gets cooled to \[{{42}^{o}}C\], then the temperature of the surroundings is   [MP PET 1997]
  A)
             \[{{30}^{o}}C\]                     done clear
  B)
             \[{{36}^{o}}C\] done clear
  C)
             \[{{26}^{o}}C\]                     done clear
  D)
             \[{{20}^{o}}C\] done clear
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• question_answer15)
   The rates of cooling of two different liquids put in exactly similar calorimeters and kept in identical surroundings are the same if                                                           [MP PMT/PET 1998]
  A)
             The masses of the liquids are equal done clear
  B)
             Equal masses of the liquids at the same temperature are taken done clear
  C)
             Different volumes of the liquids at the same temperature are taken done clear
  D)
             Equal volumes of the liquids at the same temperature are taken done clear
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• question_answer16)
  A body cools from \[{{60}^{o}}C\] to \[{{50}^{o}}C\] in 10 minutes. If the room temperature is \[{{25}^{o}}C\] and assuming Newton's law of cooling to hold good, the temperature of the body at the end of the next  10 minutes will be [MP PMT/PET 1998; BHU 2000; Pb. PMT 2001]
  A)
             \[{{38.5}^{o}}C\]                 done clear
  B)
             \[{{40}^{o}}C\] done clear
  C)
             \[{{42.85}^{o}}C\]               done clear
  D)
             \[{{45}^{o}}C\] done clear
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• question_answer17)
  The temperature of a liquid drops from \[365K\] to 361 K in 2 minutes. Find the time during which temperature of the liquid drops from \[344\ K\] to \[342K\]. Temperature of room is \[293\ K\]                                         [RPET 1997]
  A)
             84 sec                                       done clear
  B)
             72 sec done clear
  C)
             66 sec                                       done clear
  D)
             60 sec done clear
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• question_answer18)
  A body cools from \[{{50.0}^{o}}C\] to \[{{49.9}^{o}}C\] in \[5\ s\]. How long will it take to cool from \[{{40.0}^{o}}C\] to \[{{39.9}^{o}}C\]? Assume the temperature of surroundings to be \[{{30.0}^{o}}C\] and Newton's law of cooling to be valid                                                      [CBSE PMT 1994]
  A)
             2.5 s                                          done clear
  B)
             10 s done clear
  C)
             20 s                                           done clear
  D)
             5 s done clear
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• question_answer19)
   A container contains hot water at \[{{100}^{o}}C\]. If in time \[{{T}_{1}}\] temperature falls to \[{{80}^{o}}C\] and in time \[{{T}_{2}}\] temperature falls to \[{{60}^{o}}C\] from \[{{80}^{o}}C\], then                                              [CPMT 1997]
  A)
             \[{{T}_{1}}={{T}_{2}}\]      done clear
  B)
             \[{{T}_{1}}>{{T}_{2}}\] done clear
  C)
             \[{{T}_{1}}<{{T}_{2}}\]      done clear
  D)
             None done clear
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• question_answer20)
   Hot water kept in a beaker placed in a room cools from \[{{70}^{o}}C\] to 60°C in 4 minutes. The time taken by it to cool from \[{{69}^{o}}C\] to \[{{59}^{o}}c\] will be                                            [JIPMER 1999]
  A)
             The same 4 minutes          done clear
  B)
             More than 4 minutes done clear
  C)
             Less than 4 minutes           done clear
  D)
             We cannot say definitely done clear
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• question_answer21)
  Newton?s law of cooling, holds good only if the temperature difference between the body and the surroundings is [BHU 2000]
  A)
             Less than \[{{10}^{o}}C\] done clear
  B)
             More than \[{{10}^{o}}C\] done clear
  C)
             Less than \[{{100}^{o}}C\]      done clear
  D)
             More than \[{{100}^{o}}C\] done clear
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• question_answer22)
  In a room where the temperature is \[{{30}^{o}}C\], a body cools from \[{{61}^{o}}C\] to \[{{59}^{o}}C\] in 4 minutes. The time (in min.) taken by the body to cool from \[{{51}^{0}}C\]to \[{{49}^{0}}C\] will be [UPSEAT 2000]
  A)
             4 min                                        done clear
  B)
             6 min done clear
  C)
             5 min                                        done clear
  D)
             8 min done clear
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• question_answer23)
  According to ?Newton?s Law of cooling?, the rate of cooling of a body is proportional to the                          [MP PET 2001]
  A)
             Temperature of the body done clear
  B)
             Temperature of the surrounding done clear
  C)
             Fourth power of the temperature of the body done clear
  D)
             Difference of the temperature of the body and the surroundings done clear
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• question_answer24)
  A body cools in 7 minutes from \[{{60}^{o}}C\] to \[{{40}^{o}}C\] What time (in minutes) does it take to cool from \[{{40}^{o}}C\] to \[{{28}^{o}}C\] if the surrounding temperature is \[{{10}^{o}}C\]? Assume Newton?s Law of cooling holds                                                           [Kerala (Engg.) 2001]
  A)
             3.5 done clear
  B)
             11 done clear
  C)
             7     done clear
  D)
             10 done clear
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• question_answer25)
  A body takes 5 minutes for cooling from \[{{50}^{o}}C\] to \[{{40}^{o}}C.\] Its temperature comes down to \[{{33.33}^{o}}C\] in next 5 minutes. Temperature of surroundings is                      [MP PMT 2002]
  A)
             \[{{15}^{o}}C\]                     done clear
  B)
             \[{{20}^{o}}C\][L1] done clear
  C)
             \[{{25}^{o}}C\]                     done clear
  D)
             \[{{10}^{o}}C\] done clear
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• question_answer26)
  The temperature of a body falls from \[{{50}^{o}}C\]to \[{{40}^{o}}C\] in 10 minutes. If the temperature of the surroundings is \[{{20}^{o}}C\]Then temperature of the body after another 10 minutes will be                                  [Pb. PMT 2002]
  A)
             \[{{36.6}^{o}}C\]                 done clear
  B)
             \[{{33.3}^{o}}C\] done clear
  C)
             \[{{35}^{o}}C\]                     done clear
  D)
             \[{{30}^{o}}C\] done clear
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• question_answer27)
  It takes 10 minutes to cool a liquid from 61oC to 59oC. If room temperature is 30oC then time taken in cooling from 51oC to 49oC is                                                                             [RPET 2003]
  A)
             10 min                                      done clear
  B)
             11 min done clear
  C)
             13 min                                      done clear
  D)
             15 min done clear
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• question_answer28)
  A calorimeter of mass 0.2 kg and specific heat 900 J/kg-K. Containing 0.5 kg of a liquid of specific heat 2400J /kg-K. Its temperature falls from \[{{60}^{o}}C\,\text{to}\,\,\text{5}{{\text{5}}^{\text{o}}}C\] in one minute. The rate of cooling is                                                                   [MP PET 2003]
  A)
             5 J/s                                          done clear
  B)
             15 J/s done clear
  C)
             100 J/s                                     done clear
  D)
             115 J/s done clear
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• question_answer29)
  According to Newton?s law of cooling, the rate of cooling of a body is proportional to \[{{(\Delta \theta )}^{n}}\], where \[\Delta \theta \] is the difference of the temperature of the body and the surroundings, and n is equal to                                                                        [AIEEE 2003]
  A)
             One                                          done clear
  B)
             Two done clear
  C)
             Three                                       done clear
  D)
             Four done clear
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• question_answer30)
  The initial temperature of a body is 80°C.  If its temperature falls to 64°C in 5 minutes and in 10 minutes to 52°C then the temperature of surrounding will be          [MP PMT 2003]
  A)
             26°C                                          done clear
  B)
             49°C done clear
  C)
             35°C                                          done clear
  D)
             42°C done clear
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• question_answer31)
  A liquid cools from 50 o C to 45 o C in 5 minutes and from  45 o C to 41.5 o C in the next 5 minutes. The temperature of the surrounding is                                                                 [BCECE 2004]
  A)
             27 o C                                        done clear
  B)
             40.3 o C done clear
  C)
             23.3 o C                                     done clear
  D)
             33.3 o C done clear
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• question_answer32)
  A cup of tea cools from 65.5o C to 62.5 o C in one minute in a room of 22.5 o C. How long will the same cup of tea take, in.............. minutes, to cool from 46.50 o C to 40.5 o C in the same room ? (choose nearest value)                [Kerala PMT 2004]
  A)
             1     done clear
  B)
             2 done clear
  C)
             3     done clear
  D)
             4 done clear
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• question_answer33)
  The temperature of a body falls from 62oC to 50oC in 10 minutes. If the temperature of the surroundings is 26oC, the temperature in next 10 minutes will become    [RPMT 2002]
  A)
             42oC                                          done clear
  B)
             40oC done clear
  C)
             56oC                                          done clear
  D)
             55oC done clear
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• question_answer34)
  A body takes 5 minutes to cool from 90oC to 60oC. If the temperature of the surroundings is 20oC, the time taken by it to cool from 60oC to 30oC will be.     [RPMT 2003]
  A)
             5 min                                        done clear
  B)
             8 min done clear
  C)
             11 min                                      done clear
  D)
             12 min done clear
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• question_answer35)
  An object is cooled from 75°C to 65°C in 2 minutes in a room at 30°C. The time taken to cool another object from 55°C to 45°C in the same room in minutes is [EAMCET (Med.) 1996]
  A)
             4     done clear
  B)
             5 done clear
  C)
             6     done clear
  D)
             7 done clear
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• question_answer36)
  A body takes 5 minute to cool from 80°C to 50°C. How much time it will take to cool from 60°C to 30°C, if room temperature is 20°C.                                                     [RPET 1998]
  A)
             40 minute                               done clear
  B)
             9 minute done clear
  C)
             30 minute                               done clear
  D)
             20 minute done clear
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• question_answer37)
  A cane is taken out from a refrigerator at 0°C. The atmospheric temperature is 25°C. If t1 is the time taken to heat from 0°C to 5°C and t2 is the time taken from 10°C to 15°C, then                                            [Orissa JEE 2005]
  A)
             \[{{t}_{1}}>{{t}_{2}}\]        done clear
  B)
             \[{{t}_{1}}<{{t}_{2}}\] done clear
  C)
             \[{{t}_{1}}={{t}_{2}}\]        done clear
  D)
             There is no relation done clear
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