This set of Engineering Materials & Metallurgy Multiple Choice Questions & Answers (MCQs) focuses on “Thermal Properties”.
1. The response of a material due to the function of heat is known as __________
a) Mechanical property
b) Electrical property
c) Chemical property
d) Thermal property
Explanation: Mechanical properties deal with the effects of external forces, while electric properties deal with the effect of the flow of electricity, and chemical properties are related to a material’s effects due to reaction with other substances. Thermal properties deal with heat and temperature effects on the material.
3. Specific heat of materials is expressed in terms of __________
a) W/m K
c) J/kg K
Explanation: Specific heat capacity of a material is an intensive property expressed in terms of J/kg K. Thermal conductivity, heat capacity, and specific volume are expressed in terms of W/m K, J/K, and m3/kg correspondingly.
4. What effect does the addition of thermal energy have on a material?
a) Thermal contraction
b) Thermal expansion
c) No change
Explanation: Addition of heat or thermal energy results in an increase in magnitude as a theory of basic laws of thermodynamics. Hence, on the addition of thermal energy, thermal expansion occurs.
5. Which term is used to define the temperature at which a substance changes its status from solid to liquid?
a) Boiling point
b) Melting point
c) Condensation point
d) Freezing point
Explanation: The temperature at which a substance changes from solid state to liquid is known as the melting point; here the temperatures of solid and liquid are in equilibrium. The shift of liquid state to solid is known as the freezing point. The transition from gaseous state to liquid is known as condensation, while that of liquid to gaseous is known as the boiling point.
6. The melting point of Iron (Fe) is _________
Explanation: The melting point of Iron is 1538oC, whereas the melting points of aluminum (Al), zinc (Zn), and copper (Cu) are 660oC, 419oC, and 1084oC in that order.
7. The ability of a body to withstand sudden and severe temperature changes is known as________
a) Thermal shock resistance
b) Thermal resistance
c) Thermal transmittance
Explanation: Thermal shock resistance is the ability of a body to withstand sudden and severe temperature changes. Thermal resistance is a property by which a material resists a heat flow. Thermal transmittance is the rate of transfer of heat through one square meter, divided by the difference in temperature. The thermal admittance is known as the knack of a material to transmit heat when there is temperature variation on its opposite sides.
9. What effect do thermal variations in volume have on a body?
d) Phase transformation
Explanation: Cracking is the effect of thermal variation in the volume of a body. Expansion, contraction, and phase transformation are the ways in which these volume changes occur, i.e. they are causes, and not effects.
10. The temperature at which plastics begin to become softer and defer under a load is known as _________
a) Softening point
b) Melting point
c) Eutectic point
d) Heat distortion point
Explanation: Heat distortion point is the temperature at which plastics begin to become softer and defer under a load. The softening point is the temperature at which a flat-ended needle of 1 mm2 penetrates the test same at 1 mm2 depth. Eutectic point the temperature at which a mixture freezes or melts. The melting point is the temperature at which the state of the body changes from solid to liquid.
Sanfoundry Global Education & Learning Series – Engineering Materials & Metallurgy.
To practice all areas of Engineering Materials & Metallurgy, here is complete set of 1000+ Multiple Choice Questions and Answers.