Thermal Properties of Matter-Quiz-18

 

THERMAL PROPERTIES OF MATTER QUIZ-18

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.

Q171. Calculate the compressional force required to prevent the metallic rod of length l cm and cross-sectional area A cm^2 when heated through t°C, from expanding lengthwise. Young’s modulus of elasticity of the metal is E and mean coefficient of linear expension is α per degree celsius

•  EAαt
•  EAαt/(1+αt)
•  EAαt/(1-at)
•  Elαt

Solution

Q172. 250 g of water and equal volume of alcohol of mass 200 g are replaced successively in the same calorimeter and cool from 606°C to 55° C in 130 s and 67 s, respectively. If the water equivalent of the calorimeter is 10 g, then the specific heat of alcohol in cal/g-°C is

•  1.30
•  0.67
•  0.62
•  0.985

Solution

Q173. Calorie is defined as the amount of heat required to raise temperature of 1 g of water by 1 ℃ and it is defined under which of the following conditions?

•   From 14.5℃ to 15.5℃ at 760 mm of Hg
•  From 98.5℃ to 99.5℃ at 760 mm of Hg
•  From 13.5℃ to 14.5℃ at 76 mm of Hg
•  From 3.5℃ to 4.5℃ at 76 mm of Hg

Solution
173 (a) 1 calorie is the heat required to raise the temperature of 1 g of water from 14.5℃ to 15.5℃ at 760 mm of Hg.

Q174. TA flask of mercury is sealed off at 20°C and is completely filled with mercury. If the bulk modulus for mercury is 250 MPa and the coefficient of volume expansion of mercury is 1.82×10^(-4)/°C and the expension of glass is ignored, then pressure of mercury within the flask at 100°C will be

•  100 MPa
•  72 MPa
•  36 MPa
•  24 MPa

Solution

Q175. Three rods AB,BC and BD of same length l and cross section A are arranged as shown. The end D is immersed in ice whose mass is 440 g and is at 0°C. The end C is maintained at 100°C. Heat is supplied at constant rate of 200 cal/s. Thermal conductivities of AB,BC and BD are K,2K and K/2, respectively. Time after which whole ice will melt is (K=100 cal/m-s-℃, A=10 cm²,l=1 m)

•  400 s
•  600 s
•  700 s
•  800 s

Solution
 

Q176. A wall is made up of two layers A and B. The thickness of the two layers is the same, but materials are different. The thermal conductivity of A is double than that of B. In thermal equilibrium the temperature difference between the two ends is 36℃. Then the difference of temperature at the two surfaces of A will be

•  6℃
•  12℃
• 18℃
•  24℃

Solution
176 (b) Suppose thickness of each wall is x then

Q177. An iron tyre is to be fitted onto a wooden when 1.0 m in diameter. The diameter of the tyre is 6 mm smaller than that of wheel. The tyre should be heated so that its temperature increases by a minimum of (coefficient of volume expansion of iron is 3.6×10^(-5)/°C)

•  167°C
•  334°C
•  500°C
•  1000°C

Solution

Q178. Two rods, one of aluminium and the other made of steel, having initial length l_1 and l_2 are connected together to form a single rod of length l_1+l_2. The coefficients of linear expansion for aluminium and steel are α_a and α_s respectively. If the length of each rod increases by the same amount when their temperature are raised by t℃, then find the ratio l_1/((l_1+l_2)).

•  α_s/α_a
•  α_a/α_s
•  α_s/((α_a+α_s))
•  α_a/((α_(a+) α¬_s))

Solution

Q179. A 2 g bullet moving with a velocity of 200 m/s is brought to a sudden stoppage by an obstacle. The total heat produced goes to the bullet. If the specific heat of the bullet is 0.03 cal/g-°C, the rise in its temperature will be

•  158.0°C
•  15.80°C
•  1.58°C
•  >0.1580°C

Solution

Q180. Three discs, A,B and C having radii 2 m, 4 m and 6 m respectively are coated with carbon black on their outer surfaces. The wavelengths corresponding to maximum intensitios are 300 nm, 400 nm and 500 nm respectively. The power radiated by them are Q_A,Q_Band Q_C respectively

•  Q_A is maximum
•  Q_B is maximum
•  Q_c is maximum
• Q_A=Q_B=Q_C

Solution
180 (b)