1 The principle of conservation of heat energy states that
that when an object is at constant temperature or is in thermal equilibrium, it is losing and gaining heat at equal rates.
the heat lost by a hot body is equal to the heat gained by the cold body in any system provided there is no heat exchange between the substances involved and their surrounding
It is defined as the process in which molecules move from area of high concentration to another area of low concentration until an equilibrium concentration is established within the system under consideration
(P+aV2)(V−b)=RT
2 Which of the following statements is always true for a reaction in which there is no non-expansion work?
ΔH=qp
ΔU=qp
All of the above
None of the above
3 If the specific heat capacity of water initially is
4.2×103
per kg per K and
g=10m/s2
, the difference in temperature of water between the top and bottom of a 210 m high water fall is ----------
0.05oC
0.5oC
1.0oC
4.2oC
4 The latent heat of fusion of pure water is
334kJ/kg
. How much energy would it take to melt 3 kg of ice at
0oC
to water at
0oC
111 kJ
334 kJ
668 kJ
1 000 kJ
5 Which of the following is NOT true?
evaporation occurs at any temperature of a liquid
boiling takes place only at the surface of the liquid
evaporation occurs only at the surface of a liquid
boiling of a liquid takes place at a definite temperature and pressure
6 Hooke’s law states that
the force applied on elastic material is directly proportional to the acceleration produced provided the elastic limit is not exceeded.
the force applied on elastic material is directly proportional to the extension produced provided the elastic limit is exceeded.
the escape thrust applied on elastic material is directly proportional to the extension produced provided the elastic limit is not exceeded.
the force applied on elastic material is directly proportional to the extension produced provided the elastic limit is not exceeded.
7 The absolute zero temperature refers to the temperature at which
pure ice, water and water vapour at normal atmospheric pressure are in equilibrium
theoretically all thermal motions will cease
pure ice melts at normal atmospheric pressure
pure ice ecomes steam at atmospheric pressure
8 Tin melts at 232 under standard atmospheric pressure. Express this temperature in kelvin
449.16K
505.15K
60.91K
96.19K
9 An ungraduated mercury thermometer attached to a millimeter scale reads 22.8mm in ice and 242mm in steam at standard pressure. What will the millimeter read when the temperature is 20^{o} C?
66.64mm
43.84mm
219.20mm
34.54mm
10 Two bodies may be said to be in thermal equilibrium if
the bodies are thermally insulated from one another
the bodies are not in thermal equlibrium with another body
if one body loses heat to the other
if there not net flow of heat between the two bodies two bodies in thermal contact
11 Heat can be defined as------------------------
the change in temperature of a body
the flow of temperature from one body to another
energy that flows from place to place as a result of the difference in temperature between them
the measure of hotness or coolness of a body
12 Thermal expansion of a solid material depends on the following EXCEPT
the nature of the material making up the solid
the range of the temperature change
the initial dimensions of the solid
average translational motion of constituent atoms of the material
13 Calculate the work done against external atmospheric pressure when 1 g of water changes to
1672cm3
of steam. Take the atmospheric pressure as
1.013×105Nm−2
169.3 J
342.4 J
226.2 J
143.5 J
14 The statement "Heat lost by hot object is equal to heat gained by cold object" another way of expressing the law of conservation of ---------------------
charge
angular momentum
energy
momentum
15 Which of the following does NOT determine the amount of internal energy an object has?
temperature
amount of material
type of material
shape of the object
16 Calculate the work done against external atmospheric pressure when 1 g of water changes to
1672cm3
of steam. Take the atmospheric pressure as
1.013×105Nm−2
169.3 J
342.4 J
226.2 J
143.5 J
17 Calculate the change in internal energy of 2kg of water at 90 degree celcius when it is changed to 330m3 of steam at 100oC. The whole process occurs at atmospheric pressure. The latent heat of vaporization of water is 226106 J/kg.
4.27 MJ
3.43 kJ
45.72 mJ
543.63 J
18 Tensile strain is mathematically expressed as:
Force/Area
initial length/extension
extension/initial lenght
Stress + initial lenght
19 A certain resistance thermometer at triple point of water has resistance of
152.0Ω
. What is the temperature of the system in degrees celcius when the resistance of the thermometer is
230.51Ω
?
414.2o
C
141.0o
C
253.2o
C
80.4o
C
20 The temperature at which the tungsten filament of a 12 V and 36W lamp operates is
1730o
C. If the temperature coefficient of resistance of tungsten is
6×10−3
/K, find the resistance of the lamp at a room temperature of 20oC
10.00Ω
0.45Ω
0.39Ω
4.00Ω
a b b b c d a a d c a d d d
1. The principle of conservation of heat energy states that when an object is at constant temperature or is in thermal equilibrium, it is losing and gaining heat at equal rates.
2. None of the above statements is always true for a reaction in which there is no non-expansion work.
3. The difference in temperature of water between the top and bottom of a 210 m high water fall is 4.2oC.
4. The energy required to melt 3 kg of ice at 0oC to water at 0oC is 1,000 kJ.
5. Boiling takes place only at the surface of the liquid.
6. Hooke’s law states that the force applied on an elastic material is directly proportional to the extension produced provided the elastic limit is not exceeded.
7. Theoretically, all thermal motions will cease at absolute zero temperature.
8. Tin melts at 232oC, which is equivalent to 505.15 K.
9. The millimeter reading when the temperature is 20oC would be 43.84 mm.
10. Two bodies may be said to be in thermal equilibrium if there is no net flow of heat between the two bodies in thermal contact.
11. Heat can be defined as the energy that flows from place to place as a result of the difference in temperature between them.
12. The average translational motion of constituent atoms of the material does not affect the thermal expansion of a solid material.
13. The work done against external atmospheric pressure when 1 g of water changes to 1672 cm3 of steam is 342.4 J.
14. The statement "Heat lost by a hot object is equal to heat gained by a cold object" is another way of expressing the law of conservation of energy.
15. The shape of the object does not determine the amount of internal energy an object has.
16. The work done against external atmospheric pressure when 1 g of water changes to 1672 cm3 of steam is 342.4 J.
17. The change in internal energy of 2 kg of water at 90oC when it is changed to 330 m3 of steam at 100oC is 4.27 MJ.
18. Tensile strain is mathematically expressed as extension/initial length.
19. The temperature of the system when the resistance of the thermometer is 230.51Ω is 141.0oC.
20. The resistance of the lamp at a room temperature of 20oC is 10.00Ω.
1. The principle of conservation of heat energy states that when an object is at constant temperature or is in thermal equilibrium, it is losing and gaining heat at equal rates. This principle can be derived from the first law of thermodynamics, which states that energy cannot be created or destroyed, only transferred or converted from one form to another. In this case, heat energy is being transferred between the object and its surroundings, but the total amount of heat energy remains constant.
2. The correct statement for a reaction with no non-expansion work is ΔU=qp. This equation is based on the first law of thermodynamics, which states that the change in internal energy (ΔU) of a system is equal to the heat added to the system (q) plus the work done by the system (w). In the case of no non-expansion work, the work done is zero, so the equation simplifies to ΔU=qp.
3. To calculate the difference in temperature of water between the top and bottom of a 210 m high water fall, we can use the formula ΔT = gΔh / c, where ΔT is the temperature difference, g is the acceleration due to gravity (10 m/s^2), Δh is the height difference (210 m), and c is the specific heat capacity of water (4.2 × 10^3 J/kg·K). Plugging in the values, we get ΔT = (10 m/s^2)(210 m) / (4.2 × 10^3 J/kg·K) = 0.5°C.
4. The latent heat of fusion of pure water is 334 kJ/kg. To calculate the energy required to melt 3 kg of ice at 0°C to water at 0°C, we multiply the latent heat of fusion by the mass of the ice: Energy = (334 kJ/kg)(3 kg) = 1002 kJ = 1,002,000 J.
5. The statement that is NOT true is "boiling takes place only at the surface of the liquid." Boiling occurs throughout the liquid, not just at the surface. It is a rapid vaporization process that happens when the vapor pressure of the liquid exceeds the atmospheric pressure.
6. Hooke's law states that the force applied on an elastic material is directly proportional to the extension produced, provided the elastic limit is not exceeded. This describes the linear relationship between the force applied and the displacement or deformation of the material. Hooke's law is commonly used to describe the behavior of springs.
7. The absolute zero temperature refers to the temperature at which theoretically all thermal motions will cease. At absolute zero (-273.15°C or 0 Kelvin), the particles in a substance would have no kinetic energy and would be at their lowest energy state.
8. To convert the temperature at which tin melts from degrees Celsius to Kelvin, we simply add 273.15 to the Celsius temperature: 232°C + 273.15 = 505.15K.
9. To convert the readings on an ungraduated mercury thermometer to the temperature in degrees Celsius, we need to use the known values of the triple point of water (0.01°C) and the boiling point of water (100.00°C) at standard pressure. The formula to convert the reading (mm) to temperature (°C) is (reading - 22.8) / (242 - 22.8) * (100 - 0.01) + 0.01. Plugging in the values, we get (x - 22.8) / (242 - 22.8) = (20 - 0.01) / (100 - 0.01). Solving for x, we find x ≈ 43.84 mm.
10. Two bodies may be said to be in thermal equilibrium if there is no net flow of heat between the two bodies when they are in thermal contact. This means that they have the same temperature and there is no heat transfer occurring between them.
11. Heat can be defined as energy that flows from place to place as a result of the difference in temperature between the two places. It is the transfer of thermal energy from a hotter object or substance to a cooler one.
12. The thermal expansion of a solid material depends on the nature of the material making up the solid, the range of the temperature change, the initial dimensions of the solid, and the average translational motion of the constituent atoms of the material. All of these factors play a role in determining how much the solid material will expand or contract when subjected to temperature changes.
13. To calculate the work done against external atmospheric pressure when water changes to steam, we can use the formula w = pΔV, where w is the work done, p is the external pressure, and ΔV is the change in volume. In this case, the change in volume is given as 1,672 cm^3 (which is equivalent to 1.672 × 10^-3 m^3) and the atmospheric pressure is given as 1.013 × 10^5 N/m^2. Plugging in these values, we get w = (1.013 × 10^5 N/m^2)(1.672 × 10^-3 m^3) ≈ 169.3 J.
14. The statement "Heat lost by a hot object is equal to heat gained by a cold object" another way of expressing the law of conservation of energy. This law states that energy cannot be created or destroyed, only transferred or converted from one form to another. In the case of heat, the total amount of heat energy remains constant when transferred between objects.
15. The amount of internal energy an object has is determined by its temperature, the amount of material it contains, and the type of material. These factors all contribute to the object's internal energy, which is a measure of the total energy stored within the object's particles.
16. (Same as question 13)
17. To calculate the change in internal energy of water when it changes to steam, we can use the equation ΔU = m·ΔH, where ΔU is the change in internal energy, m is the mass of the water, and ΔH is the latent heat of vaporization. Given that the mass of the water is 2 kg, the latent heat of vaporization is 2.26 × 10^6 J/kg, and the whole process occurs at atmospheric pressure, we get ΔU = (2 kg)(2.26 × 10^6 J/kg) = 4.52 × 10^6 J = 4.52 MJ.
18. Tensile strain is mathematically expressed as extension/initial length. It is the ratio of the change in length of an object due to an applied force (extension) to its original length. Tensile strain measures how much a material stretches or elongates under tension.
19. To find the temperature of the system in degrees Celsius when the resistance of the thermometer is 230.51Ω, we can use the known values of resistance for the triple point of water (152.0Ω) and the equation R = R0(1 + αΔT), where R is the resistance, R0 is the resistance at a reference temperature, α is the temperature coefficient of resistance, and ΔT is the change in temperature. Rearranging the equation to solve for ΔT, we get ΔT = (R - R0) / (R0α) = (230.51Ω - 152.0Ω) / (152.0Ω × 6 × 10^-3/K) = 414.2°C.
20. To find the resistance of the lamp at a room temperature of 20°C, we can use the formula R = R0(1 + αΔT), where R is the resistance at the desired temperature, R0 is the resistance at the reference temperature, α is the temperature coefficient of resistance, and ΔT is the change in temperature. Plugging in the values, we get R = (12 Ω)(1 + (6 × 10^-3/K)(1730°C - 20°C)) = 10.00Ω.