Heat and Mass Transfer The logarithmic mean temperature difference (tm) is given by (where Δt1 and Δt2 are temperature differences between the hot and cold fluids at entrance and exit) tm = loge (Δt1/Δt2)/ (Δt1 - Δt2) tm = tm = (Δt1 - Δt2) loge (Δt1/Δt2) tm = (Δt1 - Δt2)/ loge (Δt1/Δt2) tm = loge (Δt1 - Δt2)/ Δt1/Δt2 tm = loge (Δt1/Δt2)/ (Δt1 - Δt2) tm = tm = (Δt1 - Δt2) loge (Δt1/Δt2) tm = (Δt1 - Δt2)/ loge (Δt1/Δt2) tm = loge (Δt1 - Δt2)/ Δt1/Δt2 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Two balls of same material and finish have their diameters in the ratio of 2: 1 and both are heated to same temperature and allowed to cool by radiation. Rate of cooling by big ball as compared to smaller one will be in the ratio of 0.084027777777778 0.16736111111111 0.043055555555556 0.042361111111111 0.084027777777778 0.16736111111111 0.043055555555556 0.042361111111111 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Sensible heat factor is given by (where S.H. = Sensible heat, and L.H. = Latent heat) (L.H - S.H)/S.H (S.H + L.H) /S.H S.H/(S.H + L.H) S.H/(L.H - S.H) (L.H - S.H)/S.H (S.H + L.H) /S.H S.H/(S.H + L.H) S.H/(L.H - S.H) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The heat is transferred by conduction, convection and radiation in None of these Melting of ice Boiler furnaces Condensation of steam in condenser None of these Melting of ice Boiler furnaces Condensation of steam in condenser ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Unit of thermal conductivity in S.I. units is J/m² sec Option (B) and (C) above W/m °K J/m °K sec J/m² sec Option (B) and (C) above W/m °K J/m °K sec ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The heat transfer from a hot body to a cold body is directly proportional to the surface area and difference of temperatures between the two bodies. This statement is called Stefan's law First law of thermodynamics Newton's law of cooling Newton's law of heating Stefan's law First law of thermodynamics Newton's law of cooling Newton's law of heating ANSWER DOWNLOAD EXAMIANS APP