Heat Test - 6...

The length of a rod of aluminium is 1.0 m and its area of cross-section is 5 cm². Its one end is kept at 250°C and the other end at 50°C. How much heat will flow in the rod in 5 minutes? (K for Al = 2 × 10^-1 kJ/m sec °C)

A block of ice at -10°C is slowly heated and converted to steam at 100°C. Which of the following curves represents this phenomenon qualitatively?

An ice box made of styrofoam (thermal conductivity = 0.01 Jm^-1s^-1K^-1) is used to keep liquids cool. It has a total wall area, including the lid, of 0.8 m² and wall thickness of 2.0 cm. A bottle of water is placed in the box, filled with ice. If the outside temperature is 30^oC, then the rate of flow of heat into the box is (in J-s^-1)

Consider a compound slab consisting of two different materials having the same length and thickness but different thermal conductivities K and 2K. The equivalent thermal conductivity of the slab is (assume them to be connected in series)

A copper block of mass 4 kg is heated in a furnace to a temperature 425°C and then placed on a large ice block. The mass of ice that will melt in this process will be (Specific heat of copper = 500 J kg^-1°C^-1 and heat of fusion of ice = 336 kJ kg^-1)

The temperature at which the Celsius and Fahrenheit scales give the same reading is:

The temperatures of equal masses of three different liquids A, B and C are 12°C, 19°C and 28°C, respectively. The temperature when A and B are mixed is 16°C and that when B and C are mixed is 23°C. The temperature when A and C are mixed is

In which mode of transmission do heat waves travel along a straight line with the speed of light?

A brass rod of length 500 mm and diameter 3 mm is joined to a steel rod of same length and diameter at 50°C. If the coefficient of linear expansion of brass and steel are 2.5 x 10^-5 °C^-1 and 1.25 x 10^-5 °C^-1, then change in length of the combined rod at 200°C is

An electric water kettle rated 2.1 kW is filled with 1.5 kg of water at 20^oC. How many seconds does it take to reach the boiling point of water? Assume that there are no heat losses from the kettle. Specific heat capacity of water is 4200 Jkg^-1 K^-1

Ten moles of an ideal gas at constant temperature 500 K is compressed from 50 L to 5 L. Work done in the process is (Given, R = 8.31 J - mol^-1 - K^-1):

The temperature of a body on Kelvin scale is found to be xK. When it is measured by Fahreheit thermometer, it is found to be x ^oF, then the value of x is :

A body cools from 100^oC to 70^oC in 8 second. If the room temperature is 15^oC and assuming Newton's law of cooling to hold true then, the time required for the body to cool from 70^oC to 40^oC is:

We find that the temperature of air decreases as one goes up from the Earth's surface because:

At constant pressure, which of the following is true?

The temperature, at which the rms velocity of hydrogen is four times of its value at NTP is:

Newton's law of cooling holds good only if the temperature difference between the body and the surroundings is:

With same initial conditions, an ideal gas expands from volume V₁ to V₂ in three different ways. The work done by the gas is W₁ if the process is isothermal, W₂ if isobaric and W₃ if the process is adiabatic, then

The thermal conductivity of a rod is 2. What is its thermal resistivity?

If we consider the radiations emitted by the human body, then which of the following statements is true?

In an adiabatic change, the pressure and temperature of a monoatomic gas are related according to the relation , where C is equal to:

A thermos flask made of stainless steel contains several tiny lead shots. If the flask is quickly shaken up and down several times, the temperature of lead shots:

When water is heated from 0° to 10°C, its volume

If the sun becomes twice as hot as it is now then

In terms of mechanical unit, C_p - C_v = ......, where C_p and C_v are principal specific heats.