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प्रश्न
The substance which allows heat radiations to pass through is _______.
(A) iron
(B) water vapour
(C) wood
(D) dry air
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उत्तर
dry air
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संबंधित प्रश्न
A metal sphere cools at the rate of 4°C / min. when its temperature is 50°C. Find its rate of cooling at 45°C if the temperature of surroundings is 25°C.
Two copper spheres of radii 6 cm and 12 cm respectively are suspended in an evacuated enclosure. Each of them are at a temperature 15°C above the surroundings. The ratio of their rate of loss of heat is.................
- 2:1
- 1:4
- 1:8
- 8:1
The susceptibility of magnesium at 300 K is 2.4 x 10-5. At what temperature will the susceptibility increase to 3.6 x 10-5?
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?
A body cools from 80° C to 70° C in 5 minutes and to 62° C in the next 5 minutes. Calculate the temperature of the surroundings.
The density of water at 4°C is supposed to be 1000 kg m–3. Is it same at sea level and at high altitude?
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?
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
The temperature of water at the surface of a deep lake is 2°C. The temperature expected at the bottom is
A spinning wheel is brought in contact with an identical wheel spinning at identical speed. The wheels slow down under the action of friction. Which of the following energies of the first wheel decreases?
(a) Kinetic
(b) Total
(c) Mechanical
(d) Internal
The atmospheric temperature in the cities on sea-coast change very little. Explain
Water equivalent of a body is measured in ___________ .
If heat is supplied to a solid, its temperature
(a) must increase
(b) may increase
(c) may remain constant
(d) may decrease
A resistance thermometer reads R = 20.0 Ω, 27.5 Ω, and 50.0 Ω at the ice point (0°C), the steam point (100°C) and the zinc point (420°C), respectively. Assuming that the resistance varies with temperature as Rθ = R0 (1 + αθ + βθ2), find the values of R0, α and β. Here θ represents the temperature on the Celsius scale.
A metre scale made of steel is calibrated at 20°C to give correct reading. Find the distance between the 50 cm mark and the 51 cm mark if the scale is used at 10°C. Coefficient of linear expansion of steel is 1.1 × 10–5 °C–1.
A circular hole of diameter 2.00 cm is made in an aluminium plate at 0°C. What will be the diameter at 100°C? α for aluminium = 2.3 × 10–5 °C–1.
The volume of a glass vessel is 1000 cc at 20°C. What volume of mercury should be poured into it at this temperature so that the volume of the remaining space does not change with temperature? Coefficients of cubical expansion of mercury and glass are 1.8 × 10–6 °C–1 and 9.0 × 10–6 °C–1 , respectively.
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.
Our normal body temperature is ______.
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 ______.
Two objects are said to be in thermal contact if they can exchange heat energy.
Analogy
Evaporation:: 100°C: Freezing:: ______.
The degree of hotness and coldness of a body is called ______.
Heat given to a body that raises its temperature by 1°C is ______.
What is the SI unit of heat?
What condition defines thermal equilibrium between two bodies?
What physical quantity does temperature primarily indicate?
