Heat and Thermal ExpansionHard
Question
A metallic sphere having radius 0.08 m and mass m = 10 kg is heated to a temperature of 227oC and suspended inside a box whose walls are at a temperature of 27oC. The maximum rate at which its temperature will fall is : - (Take e = 1, Stefan′s constant σ = 5.8 × 10-8 Wm-2 K-4 and specific heat of the metal s = 90 cal / kg / deg, J = 4.2 J / Calorie)
Options
A.0.055 oC/s
B.0.066 oC/s
C.0.044 oC/s
D.0.003 oC/s
Solution
From Stefan’s law of cooling :
eσA (T4 - T04) = ms
⇒ 1 × 5.8 × 10-8 × π × (0.082) × (5004 - 3004)
=10 × 90 × 4.2 × ⇒ = 0.067 oC/sFrom Stefan’s law of cooling :
eσA (T4 - T04) = ms
⇒ 1 × 5.8 × 10-8 × π × (0.082) × (5004 - 3004)
=10 × 90 × 4.2 × ⇒ = 0.067 oC/s
eσA (T4 - T04) = ms
⇒ 1 × 5.8 × 10-8 × π × (0.082) × (5004 - 3004)
=10 × 90 × 4.2 ×
⇒ = 0.067 oC/sFrom Stefan’s law of cooling : eσA (T4 - T04) = ms
⇒ 1 × 5.8 × 10-8 × π × (0.082) × (5004 - 3004)
=10 × 90 × 4.2 ×
⇒ = 0.067 oC/sCreate a free account to view solution
View Solution FreeMore Heat and Thermal Expansion Questions
A steel scale is to be prepared such that the millimeter intervals are to be accurate4 within 6 × 10-5 mm.The maxim...When water is heated from 0oC to 4oC and CP and CV are specific heats at constant pressure and constant volume respectiv...Water contained in a jar at room temperature (20oC) is intended to be colled by method - I or method - II given below :M...Radiation from a black body at the thermodynamic temperature T1 is measured by a small detector at distance d1 from it. ...A stage in cell division is shown in the figure. Select the answer which gives correct identification of the stage with ...