EASY
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What is a Romer scale?

Important Questions on Thermal Properties of Matter

MEDIUM
The temperature of equal masses of the three different liquids AB and C are 12 oC, 19 oC and 28 oC, respectively. The temperature when A and B are mixed is 16 oC and when B and C are mixed is 23 oC. The temperature when A and C are mixed is
EASY

The graph between two temperature scales P and Q is shown in the figure. Between upper fixed point and lower fixed point there are 150 equal divisions of scale P and 100 divisions on scale Q. The relationship for conversion between the two scales is given by :

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MEDIUM
A body cools from 50.0 oC to 49.9 oC in 5 s. How long will it take to cool from 40.0 oC to 39.9 oC? Assume the temperature of surroundings to be 30.0 oC and Newton's law of cooling to be valid
HARD
The ends Q and R of two thin wires, PQ and RS, are soldered (joined) together. Initially each of the wires has a length of 1 m at 10°C. Now the end P is maintained at 10°C, while the end S is heated and maintained at 400°C. The system is thermally insulated from its surroundings. If the thermal conductivity of wire PQ is twice that of the wire RS and the coefficient of linear thermal expansion of PQ is 1.2×10-5 K-1, the change in length of the wire PQ is
EASY
Mercury is often used in clinical thermometers. Which one of the following properties of mercury is not a reason for this?
EASY
Coefficient of linear expansion of brass and steel rods are α1 and α2. Lengths of brass and steel rods are l1 and l2, respectively. If l2-l1 is maintained the same at all temperatures, which one of the following relations holds good?
EASY
On a temperature scale 'X', the boiling point of water is 65°X and the freezing point is -15°X. Assuming that the X scale is linear. The equivalent temperature corresponding to -95°X on the Fahrenheit scale would be
MEDIUM
In an ideal gas at temperature T, the average force that a molecule applies on the walls of a closed container depends on T as Tq . A good estimate for q is:
HARD
A certain liquid has a melting point of -50°C and a boiling point of 150°C. A thermometer is designed with this liquid and its melting and boiling points are designated at 0°L and 100°L. The melting and boiling points of water on this scale are
 
MEDIUM
An unknown metal of mass 192 g heated to a temperature of 100 °C was immersed into a brass calorimeter of mass 128 g containing 240 g of water at a temperature of 8.4 °C. Calculate the specific heat of the unknown metal if water temperature stabilizes at 21.5 °C. ( Specific heat of brass is 394 J kg-1K-1)
EASY
Ice is used in a cooler in order to cool its contents. Which of the following will speed up the cooling process?
MEDIUM
A spring - block system is resting on a frictionless floor as shown in the figure. The spring constant is 2.0 N m-1 and the mass of the block is 2.0kg . Ignore the mass of the spring. Initially the spring is in an unstretched condition. Another block of mass 1.0kg moving with a speed of 2.0m s-1 collides elastically with the first block. The collision is such that the 2.0kg block does not hit the wall. The distance, in metres, between the two blocks when the spring returns to its unstretched position for the first time after the collision is _________.

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MEDIUM
A rod, of length L at room temperature and uniform area of cross section A, is made of a metal having coefficient of linear expansion α /°C It is observed that an external compressive force F is applied on each of its ends, prevents any change in the length of the rod when its temperature rises by T K Young's modulus, Y for this metal is:
EASY
The value of coefficient of volume expansion of glycerin is 5×10-K-1. The magnitude of fractional change in the density of glycerin for a rise of 40 oC in its temperature is:
MEDIUM
A copper ball of mass 100g is at a temperature T. It is dropped in a copper calorimeter of mass 100g, filled with 170g of water at room temperature. Subsequently, the temperature of the system is found to be 75°C. T is given by:
(Given: room temperature =30°C, specific heat of copper =0.1cal g-1 °C-1)
EASY
Two identical bodies are made of a material for which the heat capacity increases with temperature. One of these is at 100 oC, while the other one is at 0 oC. If the two bodies are brought into contact, then assuming no heat loss, the final common temperature is
EASY
A faulty thermometer reads 5°C in melting ice and 95°C in steam. The correct temperature on absolute scale will be ______ K when the faulty thermometer reads 41°C.
MEDIUM
A thin paper cup filled with water does not catch fire when placed over a flame. This is because
MEDIUM
Solar energy is incident normally on the earth's surface at the rate of about 1.4 kW m-2 . The distance between the earth and the sun is 1.5×1011 m . Energy E and mass m are related by the Einstein equation, E=mc2 where c=3×108 m s-1 is the speed of light in free space. The decrease in the mass of the sun is