Which of the following statements is/are incorrect?
Which of the following statements is/are incorrect?
A temperature change of 
on the Celsius scale is equal to a temperature change of 274 K on the Kelvin scale.
Two identical calorimeters contain equal volumes of liquids A and B. Both are heated to 
above the room temperature and left to cool. From the cooling curves shown in figure, it follows that the specific heat of A is greater than that of B.
The correct options are
C Two spheres of the same material have radii 1 m and 4 m and temperatures 4000 K and 2000 K respectively. The energy radiated per second by the first sphere is greater than that of the second sphere.
D Two identical calorimeters contain equal volumes of liquids A and B. Both are heated to above the room temperature and left to cool. From the cooling curves shown in figure, it follows that the specific heat of A is greater than that of B.
Statement (a) is incorrect. Since the size of a degree on the two scales in the same, a temperature change of 1∘C corresponds to a temperature change of 1 K. Statement (b) is correct. Since the mass and the material are the same, the volumes are equal. For the same volume. The surface are of the plate is the largest and of the sphere the smallest. The rate of loss of heat by radiation being proportional to the surface area, the plate cools the fastest and the sphere the slowest. Statement (c) is incorrect. The energy radiated by the first sphere is E1=σπR2T4=σπ×(4000)4=256×1012πσ and that by the second sphere is
E2=πσ(4)2(2000)4=256×1012πσ. Hence E1=E2 Statement (d) is also incorrect. The loss of heat by
dQdt=msdθdt=k(θ−θ0)
If s is more, dθdtwill be less. Since dθdt is larger for A, its specific heat will be smaller
C
Two spheres of the same material have radii 1 m and 4 m and temperatures 4000 K and 2000 K respectively. The energy radiated per second by the first sphere is greater than that of the second sphere.
D
Two identical calorimeters contain equal volumes of liquids A and B. Both are heated to above the room temperature and left to cool. From the cooling curves shown in figure, it follows that the specific heat of A is greater than that of B.
Statement (a) is incorrect. Since the size of a degree on the two scales in the same, a temperature change of 1∘C corresponds to a temperature change of 1 K. Statement (b) is correct. Since the mass and the material are the same, the volumes are equal. For the same volume. The surface are of the plate is the largest and of the sphere the smallest. The rate of loss of heat by radiation being proportional to the surface area, the plate cools the fastest and the sphere the slowest. Statement (c) is incorrect. The energy radiated by the first sphere is E1=σπR2T4=σπ×(4000)4=256×1012πσ and that by the second sphere is
E2=πσ(4)2(2000)4=256×1012πσ. Hence E1=E2 Statement (d) is also incorrect. The loss of heat by
dQdt=msdθdt=k(θ−θ0)
If s is more, dθdtwill be less. Since dθdt is larger for A, its specific heat will be smaller
