Multiple Choice QuestionsAn external pressure P is applied on a cube at 0°C so that it is equally compressed from all sides.K is the bulk modulus of the material of the cube and α is its coefficient of linear expansion. Suppose we want to bring the cube to its original size by heating. The temperature should be raised by
3α/PK
3PKα
P/3αK
P/3αK
A long metallic bar is carrying heat from one of its ends to the other end under steady-state. The variation of temperature θ along the length x of the bar from its hot end is best described by which of the following figure.
One end of a thermally insulated rod is kept at a temperature T1 and the other at T2. The rod is composed of two sections of lengths
(k2
(k2
(k1
(k1
If Cp and Cv denote the specific heats of nitrogen per unit mass at constant pressure and constant volume respectively, then
Cp – Cv = R/28
Cp −Cv = R/14
Cp −Cv = R
Cp −Cv = R
Assuming the sun to be a spherical body of radius R at a temperature of T K, evaluate the total radiant power, incident on Earth, at a distance r from the Sun.
where r0 is the radius of the Earth and σ is Stefan’s constant
Two rigid boxes containing different ideal gases are placed on a table. Box A contains one mole of nitrogen at temperature T0, while Box B contains one mole of helium at temperature (7/3) T0. The boxes are then put into thermal contact with each other and heat flows between them until the gases reach a common final temperature. (Ignore the heat capacity of boxes). Then, the final temperature of the gases, Tf, in terms of T0 is
A heater coil is cut into two equal parts and only one part is now used in the heater. The heat generated will now be
doubled
four times
one fourth
one fourth
If the temperature of the sun were to increase from T to 2T and its radius from R to 2R, then the ratio of the radiant energy received on earth to what it was previously will be
4
16
32
32
A radiation of energy E falls normally on a perfectly reflecting surface. The momentum transferred to the surface is
E/c
2E/c
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