Field Theory Answers

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

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

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

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

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

An ideal gas is contained in two metal cylinders X and Y connected by a tap which is initially closed. The volume and pressure of the gas in the cylinders are as attached.When the tap connecting the two cylinders is opened, what will be the final pressure, in Pa, in the vessel? Assume that the temperature remains constant
Click here to see exhibit




2.4×105

3.5×105

4.2×105

5.0×105

19 2 bulbs X and Y are filled with an ideal gas and connected by a capillary tube. The volume of bulb X is three times that of bulb Y. The number of gas molecules in X and Y are 2N and N respectively. If the temperature of the gas in Y is 300 K, what is the temperature of the gas in X
150 K
200 K
450 K
600 K

16 A student tries to determine the specific latent heat of vaporisation of a liquid by an electrical method. A heater is used to boil the liquid and when the liquid is boiling, the mass of liquid vaporised per second is measured at two different powers for the heater. At the power of 40 W and 80 W, the liquid is vaporised at the rate of 0.0417
kgs−1
and 0.0893
kgs−1
respectively. What is the best estimate of the specific latent heat of vaporisation of the liquid?

840Jkg−1

896Jkg−1

928Jkg−1

959Jkg−1
17 The temperature 47.12 °C is equivalent to
320.28 K
320.27 K
-226.03 K
-226.04 K
18 A gas cylinder is fitted with a safety valve which releases a gas when the pressure inside the cylinder reaches
2.0x106Pa
. Given the maximum mass of this gas that the cylinder can hold at 10 °C is 15 kg, what would be the maximum mass at
30∘C
?
5 kg
14 kg
20 kg
45 kg

A solid X is in thermal equilibrium with a solid Y, which is at the same temperature as a third solid Z. The three bodies are of different materials and masses. Which one of the following statements is certainly correct? of 164.9J/s, calculate the the thermal conductivity of aluminum
X and Y have the same heat capacity
X and Y have the same internal energy
It is not necessary that Y should be in thermal equilibrium with Z
There is no net transfer of energy if X is placed in thermal contact with Z
14 A hot water tank of heat capacity 5000 JK-1 contains 10 kg of water at 25 °C. What is the time taken to raise the temperature of the water to 45 °C using a heater coil of power of 3.0 kW, given that the specific heat capacity of water is 4200 Jkg-1 K-1?
61 s
280 s
310 s
610 s
15 A solid object M is made of a material with a specific capacity c and a specific latent heat of fusion L.The object is heated up at a constant rate P. Its initial temperature is below its melting point by ΔT. The time for the object to be

The specific heat of a substance at its boiling point or melting point
0
infinity
negative
between 0 and 1
10 Mass of gas is 300 gm and its specific heat at constant volume is 750 J/kg K. if gas is heated through 75°C at constant pressure of 105 N/{m^2}, it expands by volume
0.08×106cm3
. find
CP/CV
.
1.4
1.374
1.474
1.5
11 A solid ball with a mass m = 0.53 kg floats in a tank of water. The ball is made of material with a density of 400
kg/m3
. The density of water is 1000
kg/m3
. What fraction of the volume of the ball is below the waterline?
0.1
0.2
0.3
0.4
12 A slab of wood with mass m = 1.7 kg floats 78% submerged.The density of water is 1000
kg/m3
. What is the density of the wood?
720
kg/m3
780
kg/m3
850
kg/m3
900
kg/m3