Advertisements
Advertisements
Question
A metal ball cools from 64 °C to 50 °C in 10 minutes and to 42 °C in next 10 minutes. The ratio of rates of fall of temperature during the two intervals is _______.
Options
`4/7`
`7/4`
2
2.5
Advertisements
Solution
`7/4`
Rate of fall of temperature in first 10 minutes = R1 = `(64 - 50)/10`.°C/min = 1.4°C/min
Rate of fall of temperature in next 10 minutes = R2 = `(50 - 42)/10`.°C/min = 0.8°C/min
⇒ `R_1/R_2 = 7/4`
APPEARS IN
RELATED QUESTIONS
What is the temperature of the triple-point of water on an absolute scale whose unit interval size is equal to that of the Fahrenheit scale?
A body cools from 62°C to 54°C in 10 minutes and to 48°C in the next 10 minutes. Find the temperature of the surroundings.
The susceptibility of magnesium at 300K is 1.2 x 10-5. At what temperature will the susceptibility increase to 1.8 X 10-5?
Does the temperature of a body depend on the frame from which it is observed?
It is said that mercury is used in defining the temperature scale because it expands uniformly with temperature. If the temperature scale is not yet defined, is it logical to say that a substance expands uniformly with temperature?
Can the bulb of a thermometer be made of an adiabatic wall?
Why do marine animals live deep inside a lake when the surface of the lake freezes?
The length of a brass rod is found to be less on a hot summer day than on a cold winter day as measured by the same aluminium scale. Can we conclude that brass shrinks on heating?
A spherical shell is heated. The volume changes according to the equation Vθ = V0 (1 + γθ). Does the volume refer to the volume enclosed by the shell or the volume of the material making up the shell?
Which of the curves in the following figure represents the relation between Celsius and Fahrenheit temperatures?
If the temperature of a uniform rod is slightly increased by ∆t, its moment of inertia I about a line parallel to itself will increase by
Is heat a conserved quantity?
When a solid melts or a liquid boils, the temperature does not increase even when heat is supplied. Where does the energy go?
The atmospheric temperature in the cities on sea-coast change very little. Explain
Should a thermometer bulb have large heat capacity or small heat capacity?
The heat capacity of a body depends on
(a) the heat given
(b) the temperature raised
(c) the mass of the body
(d) the material of the body
A steel wire of cross-sectional area 0.5 mm2 is held between two fixed supports. If the wire is just taut at 20°C, determine the tension when the temperature falls to 0°C. Coefficient of linear expansion of steel is 1.2 × 10–5 °C–1 and its Young's modulus is 2.0 × 10–11 Nm–2.
‘An object contains more heat’- is it a right statement? If not why?
Define one mole.
Two tumblers of A and B have water at 50°C temperature. If the water from A and B is poured into tumbler C. The temperature of C is ______.
Give reasons for the following:
Hot metal ball of 80° C is dipped into water of 80°C. The ball will not contract.
Two identical beakers A and B contain equal volumes of two different liquids at 60°C each and is left to cool down. Liquid in A has a density of 8 × 102 kg/m3 and specific heat of 2000 J kg-1 K-1 while the liquid in B has a density of 103 kg m-3 and specific heat of 4000 J kg-1 K-1. Which of the following best describes their temperature versus time graph schematically? (assume the emissivity of both the beakers to be the same.)
An earthen pitcher loses 1 gm of water per minute due to evaporation. If the water equivalent of the pitcher is 0.5 kg and the pitcher contains 9.5 kg of water, calculate the time required for the water in a pitcher to cool to 28°C from the original temperature of 30°C. Neglect radiation effects. The latent heat of vaporization in this range of temperature is 580 Cal/gm and the specific heat of water is 1 Cal/gm°C.
Heat given to a body that raises its temperature by 1°C is ______.
Which statement about states of matter is most accurate?
What condition defines thermal equilibrium between two bodies?
What physical quantity does temperature primarily indicate?
What is the best description of heat in thermodynamics?
