Thermal Properties of Matter-Quiz-7

 

THERMAL PROPERTIES OF MATTER QUIZ-7

Dear Readers,

JEE Advanced Physics Syllabus can be referred by the IIT aspirants to get a detailed list of all topics that are important in cracking the entrance examination. JEE Advanced syllabus for Physics has been designed in such a way that it offers very practical and application-based learning to further make it easier for students to understand every concept or topic by correlating it with day-to-day experiences. In comparison to the other two subjects, the syllabus of JEE Advanced for physics is developed in such a way so as to test the deep understanding and application of concepts.

Q61. Compared to a burn due to water at 100°C, a burn due to steam at 100°C is

•  More dangerous
•  Less dangerous
•  Equally dangerous
•  None of these

Solution

62. A pendulum clock having copper rod keeps correct time at 20℃. It gains 15 s per day if cooled to 0°C. The coefficient of linear expansion of copper is

•  1.7×10^(-4)/°C
•  1.7×10^(-5)/°C
•  3.4×10^(-4)/°C
•  3.4×10^(-5)/°C

Solution

Q63. A beaker contains 200 g of water. The heat capacity of the beaker is equal to that of 20 g of water. The initial temperature of water in the beaker is 20°C. If 440 g of hot water at 92°C is poured in it, the final temperature (neglecting radiation loss) will be nearest to

•   58°C
•  68°C
•  73°C
•  78°C

Solution

Q64. The earth receives on its surface radiation from the sun at the rate of 1400 W/m². The distance of the centre of the sun from the surface of the earth is 1.5×10¹¹ m and the radius of the sun is 7.0×10⁸ m. Treating sun as a black body, it follows from the above data that its surface temperature is

•  5801 K
•  10^{^6} K
•  50.1 K
•  5801°C

Solution

Q65. A solid copper sphere (density ρ and specific heat capacity c) of radius r at an initial temperature 200K is suspended inside a chamber whose walls are at almost 0K. The time required (in μ s) for the temperature of the sphere to drop to 100 K is

•  72/2 rρc/σ
•  7/72 rρc/σ
•  27/7 rρc/σ
•  7/27 rρc/σ

Solution
 

Q66. The design of a physical instrument requires that there be a constant difference in length of 10 cm between an iron rod and a copper cylinder laid side by side at all temperatures. If α_Fe=11×10^(-6)/℃ and α_cu=17×10^(-6)/°C, their length may be

•  28.3 cm,18.3 cm
•  23.8 cm, 13.8 cm
• 23.9 cm, 10.9 cm
•  27.5 cm,14.5 cm

Solution

Q67. Six identical conducting rods are joined as shown in Figure. Points A and D are maintained at temperatures 200°C and 20°C, respectively. The temperature of junction B will be

•  120°C
•  100°C
•  140°C
•  80°C

Solution

Q68. The coefficient of linear expansion for a certain metal varies with temperature as α(T). If L_0 is the initial length of the metal and the temperature of metal is changed from T_0 to (T_0>T), then

•  
  
•  
  
•  
  
•  L>L_0

Solution

Q69. 5 g of water at 30° C and 5 g of ice at -20°C are mixed together in a calorimeter. Find the final temperature of the mixture. Assume water equivalent of calorimeter to be negligible, sp. heats of ice and water are 0.5 and 1 cal/g C°, and latent heat of ice is 80 cal/g

•  0°C
•  10°C
•  -30°C
•  >10°C

Solution

Q70. Which of the following, when mixed, would raise the temperature of 20 g of water at 30° C most?

•  20 g of water at 40°C
•  40 g of water at 35°C
•  10 g of water at 50°C
• 4 g of water at 80°C

Solution