Heat and Mass Transfer Quizz

1. All radiations in the black body are

• (A)Absorbed

• (B)Reflected

• (C)Transmitted

• (D)Refracted

2. The heat is absorbed by

• (A) Condenser

• (B) Evaporator

• (C) Compressor

• (D) Thermostat

3. If the body is at thermal equilibrium, then the

• (A) Emissivity = absorptivity

• (B) Emissivity ˃ absorptivity

• (C) Emissivity ˂ absorptivity

• (D) None of the above

4. Heat transfer takes place according to

• (A) First Law of Thermodynamics

• (B) Second Law of Thermodynamics

• (C) Third Law of Thermodynamics

• (D) Zeroth Law of Thermodynamics

5. What happens when the thickness of insulation on a pipe exceeds the critical value?

• (A) Heat transfer rate increases

• (B) Heat transfer rate decreases

• (C) Heat transfer rate remain constant

• (D) none of these

6. In heat exchangers, the value of logarithmic mean temperature difference should be

• (A) maximum possible,

• (B) minimum possible,

• (C) zero;

• (D) constant

7. Units for thermal conductivity

• (A) J/kg.K

• (B) J/mol.K

• (C) J.ohm/sec.K2

• (D) W/m.K

8. The process of heat transfer from one particle of the body to another without actual motion of the particle is called

• (A)Radiation

• (B)Conduction

• (C)Convection

• (D)Radiation

9. The body which absorbs all radiations incident upon it, is called as

• (A) Black body

• (B) White body

• (C) Opaque body

• (D) Transparent body

10. Thermal conductivity of wood depends on

• (A) Moisture

• (B) Density

• (C) Temperature

• (D) All of the above