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

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

0.042361111111111

0.16736111111111

0.043055555555556

0.084027777777778

0.042361111111111

0.16736111111111

0.043055555555556

0.084027777777778

ANSWER DOWNLOAD EXAMIANS APP

Heat and Mass Transfer
The expression Q = ρ AT4 is called

Stefan-Boltzmann equation

Newton Reichmann equation

Fourier equation

Joseph-Stefan equation

Stefan-Boltzmann equation

Newton Reichmann equation

Fourier equation

Joseph-Stefan equation

ANSWER DOWNLOAD EXAMIANS APP

Heat and Mass Transfer
Temperature of steam at around 540°C can be measured by

Thermistor

None of these

Thermocouple

Thermometer

Thermistor

None of these

Thermocouple

Thermometer

ANSWER DOWNLOAD EXAMIANS APP

Heat and Mass Transfer
Two long parallel surfaces each of emissivity 0.7 are maintained at different temperatures and accordingly have radiation heat exchange between them. It is desired to reduce 75% of the radiant heat transfer by inserting thin parallel shields of emissivity 1 on both sides. The number of shields should be

Two

Three

Four

One

Two

Three

Four

One

ANSWER DOWNLOAD EXAMIANS APP

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

P = 0, x = 1 and a = 0

P= 1, T = 0 and a = 0

X = 0, a + p = 0

P = 0, x = 0 and a = 1

P = 0, x = 1 and a = 0

P= 1, T = 0 and a = 0

X = 0, a + p = 0

P = 0, x = 0 and a = 1

ANSWER DOWNLOAD EXAMIANS APP

Heat and Mass Transfer
The ratio of the emissive power and absorptive power of all bodies is the same and is equal to the emissive power of a perfectly black body. This statement is known as

Wien's law

Stefan's law

Kirchhoff's law

Planck's law

Wien's law

Stefan's law

Kirchhoff's law

Planck's law

ANSWER DOWNLOAD EXAMIANS APP

Heat and Mass Transfer

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

Heat and Mass Transfer The expression Q = ρ AT4 is called

Heat and Mass Transfer Temperature of steam at around 540°C can be measured by

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

Heat and Mass Transfer The ratio of the emissive power and absorptive power of all bodies is the same and is equal to the emissive power of a perfectly black body. This statement is known as

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

Heat and Mass Transfer
The expression Q = ρ AT4 is called

Heat and Mass Transfer
Temperature of steam at around 540°C can be measured by

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

Heat and Mass Transfer
The ratio of the emissive power and absorptive power of all bodies is the same and is equal to the emissive power of a perfectly black body. This statement is known as