CBSE
Multiple Choice QuestionsA solid sphere and a hollow sphere are heated the same temperature. Point out the true statement.
hollow sphere cools more quickly
both hollow and solid sphere cools more quickly
solid sphere cools more quickly
none of the statement is true
1 Kcal of heat flowing through a rod iron. When the rod is cut down to 4 pieces then what will be the heat flowing through each piece having same differential temperature?
1/2 Kcal
1/4 Kcal
1 Kcal
1/15 Kcal
Temperature of the star is determined by
distance
colour
size
none of these
If hot water is mixed with cold water
temperature first increases then become constant
temperature first decreases then become constant
increases continuously
first it is uncertain then it become constant
A constant pressure air thermometer gave a reading 47.5 units of volume when immersed in ice-cold water and 67 units in a boiling liquid. The boiling point of the liquid, is
125°C
100°C
135°C
112°C
For an enclosure maintained at 1000 K, the maximum radiation occurs at wavelength λm. If the temperature is raised to 2000 K, the peak will shift to
A metallic solid sphere is rotating about its diameter as axes of rotation. If the temperature is increased by 200°C, the percentage increase in its moment of inertia is (Coefficient of linear expansion of the metal = )
0.1%
0.2%
0.3%
0.4%
A vessel containing 0.1 m3 of air at 76 cm of Hg is connected to an evacuated vessel of capacity 0.09m3. The resultant air pressure is
20 cm of Hg
30 cm of Hg
40 cm of Hg
60 cm of Hg
A black body of mass 34.38 g and surface area 19.2 cm2 is at an initial temperature of 400 K. It is allowed to cool inside an evacuated enclosure kept at constant temperature 300 K. The rate of cooling is 0.04/s. The specific heat of the body is (Stefan's constant σ = 5.73 × 10-8 Jm-2K-4)
2800 J/kg-k
2100 J/kg-k
1400 J/kg-K
1200 J/kg-K
The unit of Stefan's constant is
Wm-2 K-1
Wm K-4
Wm-2 K-4
Nm-2 K-4
