Thermal Properties of Matter Test

Result

Thermal Properties of Matter Test - 57

Score
-
out of -
Rank
-
out of -

TIME Taken - -

SHARING IS CARING

If our Website helped you a little, then kindly spread our voice using Social Networks. Spread our word to your readers, friends, teachers, students & all those close ones who deserve to know what you know now.

Weekly Quiz Competition

Question 1
1 / -0

Two plastic cups are placed one inside the other. A small spacer keeps the two cups separated. How water is poured into the inner cup and a lid is put on top, as shown.
Which statement is correct?

A
The bench is heated by conduction from the bottom of the outer cups

B
The lid reduced the energy gain by convection

C
There is no thermal conduction through the sides of either cup

D
Thermal radiation is prevented by the small air gap

Solution

The outer cup is get heated by the radiation of inner cup and since the outer cup is in contact with bench so it get heated due to conduction.
Question 2
1 / -0

End $$A$$ of a copper rod is. maintained in steam chamber and other end is maintained at $$0^{\circ}C$$. Assume $$x = 0$$ at $$A$$. The $$T - x$$ graph for the rod in steady state is

A

B

C

D
None of these

Solution
Question 3
1 / -0

$$2$$ mole ideal He gas and $$3$$ mole ideal $$H_2$$ gas at constant volume find out $$C_v$$ of mixture

A
$$\dfrac{21 R}{10}$$

B
$$\dfrac{11 R}{10}$$

C
$$\dfrac{21 R}{5}$$

D
$$\dfrac{11 R}{5}$$

Solution

The given mixture of two moles of monoatomic gas mixed with three mole of diatomic gas can be given as
$$C=\dfrac{n_1C_{v_1}+n_2C_{v_2}}{n_1+n_2}$$

$$=\dfrac{2\times \dfrac{3}{2}R+3\times \dfrac{5}{2}R}{2+3}$$

$$=\dfrac{3R+15\dfrac{R}{2}}{5}=\left(\dfrac{21 R}{10}\right)$$
Question 4
1 / -0

A fixed mass of gas is taken through a process $$A\rightarrow B\rightarrow C\rightarrow A$$. Here $$A\rightarrow B$$ is isobaric $$B\rightarrow C$$ is adiabatic and $$C\rightarrow A$$ is isothermal

The pressure at $$C$$ is given by $$(\gamma=1.5)$$

A
$$\frac{10^5}{64}\,N/m^2$$

B
$$\frac{10^5}{32}\,N/m^2$$

C
zero

D
$${10}^5\,N/m^2$$

Solution
Question 5
1 / -0

Pressure of an ideal gas is increased by keeping temperature constant. The kinetic energy of molecules.

A
Decreases

B
Increases

C
Remains same

D
Increases or decreases depending on the nature of gas

Solution

Since the pressure is being increased, keeping the temperature constant, this basically implies that you are squeezing the volume of the container in which the gas is kept (a direct consequence of Boyle’s Law). Since, the volume of the container has decreased, the dimensions over which the molecules of the gas can move before colliding with the walls has also decreased. Hence, there will be greater number of collisions per unit time. But that is all that would happen.
Since the temperature is essentially held constant, and it is a common knowledge that the root mean square speed of the molecules of an ideal gas is purely a function of temperature alone, as given by V = (3RT/M)0.5, so the kinetic energy of the molecules will remain constant. There may be greater amount of energy exchange and transfer between the molecules, due to reduction in mean free path. But, the overall kinetic energy of the gas as a whole, remains the same.
Question 6
1 / -0

Water does not freeze at the bottom of the lakes in winter because :

A
ice is a good conductor of hear

B
ice reflects heat and light

C
of anomalous expansion of water between $$4^oC$$ to $$0^oC$$

D
nothing can be said

Solution

lets look at the freezing process of water in lakes :
The top layer of water which is exposed to surrounding emits heat energy to the surrounding due to which temperature of water lower , if we divide the process in two parts:

$$T>4^oC$$ : when the temperature of top layer lowers its density increases so momentarily its density is more than densities of bottom layers therefore the top layer of water sinks down

$$T\leq 4^oC$$ : now when top layers emits heat its temperature lower but density decreases so it does not sinks down and remains at the top and when freezing process will start at $$0^oc$$ it will be from top to bottom.

The ice formed on the surface is less dense than water and floats at the water surface. This layer acts as an insulation layer which prevents contact between the water bulk and the freezing surrounding, thus preventing further freezing of water
Question 7
1 / -0

A steel scale gives correct reading at $$t_1 ^oC$$. When temperature changes to $$t_2 ^oC$$, then :

A
if $$t_2> t_1$$, reading is greater that true value

B
if $$t_2> t_1$$, reading is lesser that true value

C
the reading is always equal to true value

D
the reading is always less than true value

Solution

length of scale will increase on increasing the the temperature and if length of scale will increase then it will give less value for same length which was measured using the scale at original temprature
Question 8
1 / -0

A physicist says "a body contains $$10\ joule$$ heat" but a physics learner says "this statement is correct only when the body is in liquid state". Mark correct option or options :

A
physicist statement is correct

B
physics learner's statement is correct

C
both statements are correct

D
both statements are wrong

Solution

Heat is the amount of energy transfer between a hotter body to a cooler body quantified by their temperature difference. A body cannot contain some amount of heat but can contain some amount of energy which can transferred as heat energy depending on the temperature difference.
So the first statement is incorrect
The statement given by the physicist is not valid in any state. So the statement of the learner is also wrong.
Question 9
1 / -0

A metal rod of length $$L$$ and cross-sectional area $$A$$ converts a large tank of water at temperature $$\theta_{0}$$ and a small vessel containing mass $$m$$ of water at initial temperature of $$\theta_{1}(< \theta_{0})$$. If the thermal conductivity of rod is $$K$$, then the time taken for the temperature of water in smaller vessel to become $$\theta_{2}(\theta_{1} < \theta_{2} < \theta_{0})$$ is:
(Given : Specific heat capacity of water is $$s$$ and all other heat capacities are neglected).

A
$$T = \dfrac {ms}{KA} \log \dfrac {(\theta_{0} - \theta_{1})}{(\theta_{0} - \theta_{2})}$$

B
$$T = \dfrac {Lms}{KA}\log \left (\dfrac {\theta_{0} - \theta_{1}}{\theta_{0} - \theta_{2}}\right )$$

C
$$T = \dfrac {2mLs}{KA} \left (\log \dfrac {(\theta_{0} - \theta_{1})}{\theta_{0} - \theta_{2}}\right )$$

D
None of the above

Solution
Question 10
1 / -0

In which of the following phenomena do heat waves travel along a straight line with the speed of light ?

A
Thermal conduction

B
Thermal convection

C
Thermal radiation

D
Both, thermal conduction and radiation

Solution

Thermal radiation is energy emitted by a body in the form of radiation on account of its temperature. The radiations are heat radiations and travel along straight lines with speed of light.