Thermal Properties of Matter-Quiz-15

 

THERMAL PROPERTIES OF MATTER QUIZ-15

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.

Q141. An electrically heated coil is immersed in a calorimeter containing 360 g of water at 10°C. The coil consumes energy at the rate of 90 W. The water equivalent of calorimeter and coil is 40 g. The temperature of water after 10 min is

•  4.214°C
•  42.14°C
•  30°C
•  None of these

Solution

Q142. The energy spectrum of a black body exhibits a maximum around a wavelength λ_0. The temperature of the black body is now changed such that the energy is maximum around a wavelength 3λ_0/4. The power radiated by the black body will now increase by a factor of

•  256/81
•  64/27
•  16/9
•  4/3

Solution

Q143. A body takes T minutes to cool from 62°C to 61°C when the surrounding temperature is 30°C. The time takes by the body to cool from 46°C to 45.5°C is

•   Greater than T minutes
•  Equal to T minutes
•  Less than T minutes
•  None of these

Solution

Q144. Two holes of unequal diameters d_(1 )and d_2 (d_1>d_2 ) are cut in a metal sheet. If the sheet is heated

•  Both d_1 and d_2will decrease
•  Both d_1 and d_2 will increase
•  d_1 will increase, d_2 will decrease
•  d_1 will decrease, d_2 will increase

Solution
144 (b) If the sheet is heated then both d_1 and d_2 will increase since the thermal expansion of isotropic solid is similar to true photographic enlargement

Q145. A block of wood is floating in water at 0°C. The temperature of water is slowly raised from 0°C to 10°C. With the rise in temperature the volume of block V above water level will

•  Increase
•  Decrease
•  First increase and then decrease
•  First decrease and then increase

Solution
 

Q146. Following graph shows the correct variation in intensity of heat radiations by black body and frequency at a fixed temperature

•  
  
•  
  
• 
•  
  

Solution
146 (c) As the temperature of body increases, frequency corresponding to maximum energy in radiation (v_m) increases. This is shown in graph (c)

Q147. The coefficient of thermal conductivity of copper is nine times that of steel. In the composite cylindrical bar shown in Figure, what will be the temperature at the junction of copper and steel?

•  75°C
•  67°C
•  33°C
•  25°C

Solution

Q148. The temperature of a room heated by a heater is 20°C when outside temperature is -20°C and it is 10°C when the outside temperature is -40°C. The temperature of the heater is

•  80°C
•  100°C
•  40°C
•  60°C

Solution

Q149. The rates of cooling of two different liquids put in exactly similar calorimeters and kept in identical surroundings are the same if

•  The masses of the liquids are equal
•  Equal masses of the liquids at the same temperature are taken
•  Different volumes of the liquids at the same temperature are taken
•  >Equal volumes of the liquids at the same temperature are taken

Solution

Q150. In a motor, the electrical power input is 500 W and the mechanical power output is 0.54 horse power. Heat developed in the motor in 1 h is (assuming that all the electric energy which is not converted to mechanical energy is converted to heat)is

•  4.18×10⁴cal
•  3.6×10⁵cal
•  8.6×10⁴cal
• 1.28×10⁵cal

Solution