A grey body is one whose absorptivity

Heat and Mass Transfer
A grey body is one whose absorptivity

Does not vary with temperature and. wavelength of the incident ray

Varies with temperature

Varies with wavelength of the incident ray

Is equal to its emissivity

Does not vary with temperature and. wavelength of the incident ray

Varies with temperature

Varies with wavelength of the incident ray

Is equal to its emissivity

ANSWER DOWNLOAD EXAMIANS APP

Heat and Mass Transfer
Thermal conductivity of a material may be defined as the

Quantity of heat flowing in one second through one cm cube of material when opposite faces are maintained at a temperature difference of 1°C

All of these

Heat conducted in unit time across unit area through unit thickness when a temperature difference of unity is maintained between opposite faces

Quantity of heat flowing in one second through a slab of the material of area one cm square, thickness 1 cm when its faces differ in temperature by 1°C

Quantity of heat flowing in one second through one cm cube of material when opposite faces are maintained at a temperature difference of 1°C

All of these

Heat conducted in unit time across unit area through unit thickness when a temperature difference of unity is maintained between opposite faces

Quantity of heat flowing in one second through a slab of the material of area one cm square, thickness 1 cm when its faces differ in temperature by 1°C

ANSWER DOWNLOAD EXAMIANS APP

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 = (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

tm = loge (Δt1/Δt2)/ (Δt1 - Δt2)

tm = tm = (Δt1 - Δt2) loge (Δt1/Δt2)

ANSWER DOWNLOAD EXAMIANS APP

Heat and Mass Transfer
Metals are good conductors of heat because

Their atoms collide frequently

Their atoms are relatively far apart

They have high density

They contain free electrons

Their atoms collide frequently

Their atoms are relatively far apart

They have high density

They contain free electrons

ANSWER DOWNLOAD EXAMIANS APP

Heat and Mass Transfer
Depending on the radiating properties, a body will be white when(Where a = absorptivity, p = reflectivity, x = transmissivity)

P=1, T = 0 and a = 0

P = 0, x = 0 and a = 1

X = 0, a + p = 1

P = 0, x = 1 and a = 0

P=1, T = 0 and a = 0

P = 0, x = 0 and a = 1

X = 0, a + p = 1

P = 0, x = 1 and a = 0

ANSWER DOWNLOAD EXAMIANS APP

Heat and Mass Transfer
The ratio of Nusselt number and the product of Reynold's number and Prandtl number is equal to

Grashoff number

Peclet number

Stanton number

Biot number

Grashoff number

Peclet number

Stanton number

Biot number

ANSWER DOWNLOAD EXAMIANS APP

Heat and Mass Transfer

Heat and Mass Transfer A grey body is one whose absorptivity

Heat and Mass Transfer Thermal conductivity of a material may be defined as the

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)

Heat and Mass Transfer Metals are good conductors of heat because

Heat and Mass Transfer Depending on the radiating properties, a body will be white when(Where a = absorptivity, p = reflectivity, x = transmissivity)

Heat and Mass Transfer The ratio of Nusselt number and the product of Reynold's number and Prandtl number is equal to

Heat and Mass Transfer
A grey body is one whose absorptivity

Heat and Mass Transfer
Thermal conductivity of a material may be defined as the

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)

Heat and Mass Transfer
Metals are good conductors of heat because

Heat and Mass Transfer
Depending on the radiating properties, a body will be white when(Where a = absorptivity, p = reflectivity, x = transmissivity)

Heat and Mass Transfer
The ratio of Nusselt number and the product of Reynold's number and Prandtl number is equal to