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 3:30m3 of steam at 100oC. The whole process occurs at atmospheric pressure. The latent heat of vaporization of water is 2:26106 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
Actually, I took the course in 1956 and do not need the practice. You do. Try and I am sure one of us will look your results over.
pls someone should solve dis
1. The principle of conservation of heat energy states that when an object is at constant temperature or in thermal equilibrium, it is losing and gaining heat at equal rates. This means that the heat lost by a hot body is equal to the heat gained by a cold body in any system, provided there is no heat exchange between the substances involved and their surroundings.
2. For a reaction in which there is no non-expansion work, both ΔH (change in enthalpy) and ΔU (change in internal energy) are equal to the heat exchanged at constant pressure (qp). So the correct statement is "All of the above."
3. The difference in temperature of water between the top and bottom of a 210 m high waterfall can be calculated using the formula ΔT = ghΔT, where g is the acceleration due to gravity (10 m/s^2) and h is the height (210 m). Plugging in the values, we get ΔT = (10 m/s^2) * (210 m) = 2100 K. Converting this to Celsius, we divide by 2. We get ΔT = 1050 °C, which is equal to 1.0 °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 use the formula Q = m * Lf, where Q is the heat energy, m is the mass, and Lf is the latent heat of fusion. Plugging in the values, we get Q = (3 kg) * (334 kJ/kg) = 1002 kJ.
5. The statement that is NOT true is "Evaporation occurs only at the surface of a liquid." Evaporation can occur throughout the liquid, not just at the surface.
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. The absolute zero temperature refers to the temperature at which theoretically all thermal motions will cease. At absolute zero, all molecular motion stops.
8. To convert temperature from Celsius to Kelvin, we add 273.15 to the Celsius temperature. So, 232 °C + 273.15 = 505.15 K.
9. To find the millimeter reading when the temperature is 20 °C, we need to use the linear relationship between temperature and millimeter reading. The change in the millimeter reading, Δmm, can be found by subtracting the reading in ice from the reading in steam: Δmm = 242 mm - 22.8 mm = 219.2 mm. Since the range between the ice and steam readings corresponds to 100 °C, we can set up a proportion: 100 °C is to 219.2 mm as 20 °C is to x mm. Solving for x, we get x = (20 °C/100 °C) * 219.2 mm = 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 and they are in thermal contact with each other.
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 thermal expansion of a solid material depends on the nature of the material making up the solid, the range of the temperature change, and the initial dimensions of the solid. It does not depend on the average translational motion of constituent atoms of the material.
13. To calculate the work done against external atmospheric pressure when 1 g of water changes to 1672 cm^3 of 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. Plugging in the values, we get W = (1.013 x 10^5 N/m^2) * (1672 cm^3) = 169.3 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 amount of internal energy an object has is determined by its temperature, the amount of material it contains, and the type of material. The shape of the object does not determine the amount of internal energy.
16. The work done against external atmospheric pressure when 1 g of water changes to 1672 cm^3 of steam is 169.3 J.