Thermo Dynamics

23 Questions Start DPT Test
Q1 Objective Physics Vol-2 1. Temperature MCQ
28 Jul 2026
Concept: Conversion of temperature from one scale to another
Express the temperature of 60°F in degree celsius and in kelvin.
A.
15.55°C, 273.15 K
B.
60°C, 333 K
C.
15.55°C, 288.7 K
D.
32°C, 305 K
Q2 Objective Physics Vol-2 1. Temperature MCQ
28 Jul 2026
Concept: Temperature difference measured by different scales
The temperature of an iron piece is raised from 30°C to 90°C. What is the change in its temperature on the Fahrenheit scale and on the Kelvin scale?
A.
60°F, 108 K
B.
108°F, 60 K
C.
108°F, 108 K
D.
60°F, 60 K
Q3 Objective Physics Vol-2 1. Temperature MCQ
28 Jul 2026
Concept: Conversion between an arbitrary temperature scale and the Celsius scale
On a new scale of temperature (which is linear) and called the W scale, the freezing and boiling points of water are 39°W and 239°W, respectively. What will be the temperature on the new scale, corresponding to a temperature of 39°C on the Celsius scale?
A.
78°W
B.
39°W
C.
239°W
D.
117°W
Q4 Objective Physics Vol-2 1. Temperature MCQ
28 Jul 2026
Concept: Converting readings from an arbitrary thermometer scale to the Celsius scale
An arbitrary scale has the ice point at -20° and the steam point at 180°. When the thermometer reads 5°, then find the reading of centigrade thermometer.
A.
12.5°C
B.
25°C
C.
5°C
D.
-12.5°C
Q5 Objective Physics Vol-2 1. Temperature MCQ
28 Jul 2026
Concept: Correcting temperature readings from a faulty thermometer scale
A faulty scale has its fixed points marked as 5° and 95°. The temperature of a body as measured by the faulty scale is 59°. Find the correct temperature of the body on Celsius scale.
A.
54°C
B.
59°C
C.
60°C
D.
90°C
Q6 Objective Physics Vol-2 1. Temperature MCQ
28 Jul 2026
Concept: Constant volume gas thermometer and temperature measurement
The pressures of the gas filled in the bulb of a constant volume gas thermometer are 66 cm and 88 cm of mercury column at $0^\circ C$ and $100^\circ C$, respectively. When its bulb is immersed in a liquid placed in a vessel, its pressure is 82.5 cm of mercury column. Calculate the temperature of the liquid.
A.
$65^\circ C$
B.
$75^\circ C$
C.
$82.5^\circ C$
D.
$88^\circ C$
Q7 Objective Physics Vol-2 1. Temperature MCQ
28 Jul 2026
Concept: Platinum resistance thermometer and temperature calculation
The following observations were recorded on a platinum resistance thermometer. Resistance at melting point of ice is $3.70 \Omega$, resistance at boiling point of water at normal pressure is $4.71 \Omega$ and resistance at an unknown temperature $t$ is $5.29 \Omega$. Calculate the value of temperature $t$.
A.
$101.0^\circ C$
B.
$125.5^\circ C$
C.
$157.4^\circ C$
D.
$180.2^\circ C$
Q8 Objective Physics Vol-2 1. Temperature MCQ
28 Jul 2026
Concept: Thermometry and measurement of temperature
A device used to measure temperature is
A.
Hygrometer
B.
Thermometer
C.
Barometer
D.
Calorimeter
Q9 Objective Physics Vol-2 1. Temperature MCQ
28 Jul 2026
Concept: Conversion of temperature difference between Celsius and Fahrenheit scales
A difference of temperature of $25^\circ \mathrm{C}$ is equivalent to a difference of
A.
$45^\circ \mathrm{F}$
B.
$72^\circ \mathrm{F}$
C.
$32^\circ \mathrm{F}$
D.
$25^\circ \mathrm{F}$
Q10 Objective Physics Vol-2 1. Temperature MCQ
28 Jul 2026
Concept: Temperature scale conversion and finding the point of equality
At what temperature, does the temperature in Celsius and Fahrenheit equalise?
A.
$-40^\circ$
B.
$40^\circ$
C.
$36.6^\circ$
D.
$38^\circ$
Q11 Objective Physics Vol-2 1. Temperature MCQ
28 Jul 2026
Concept: Conversion of temperature from Celsius scale to an arbitrary temperature scale
The freezing point on a thermometer is marked as $-20^\circ$ and the boiling point as $130^\circ$. A temperature of human body ($34^\circ \mathrm{C}$) on this thermometer will be read as
A.
$31^\circ$
B.
$51^\circ$
C.
$20^\circ$
D.
None of these
Q12 Objective Physics Vol-2 1. Temperature MCQ
28 Jul 2026
Concept: Conversion of temperature from Celsius scale to an arbitrary temperature scale
The freezing point on a thermometer is marked as -20° and the boiling point as 130°. A temperature of human body (34°C) on this thermometer will be read as
A.
31°
B.
51°
C.
20°
D.
None of these
Q13 Objective Physics Vol-2 1. Temperature MCQ
28 Jul 2026
Concept: Relationship between Kelvin and Fahrenheit temperature scales
The temperature of a body on Kelvin scale is found to be x Kelvin. When it is measured by Fahrenheit thermometer, it is found to be x°Fahrenheit, then the value of x is
A.
40
B.
313
C.
574.25
D.
301.25
Q14 Objective Physics Vol-2 1. Temperature MCQ
28 Jul 2026
Concept: Correcting temperature readings from a faulty thermometer scale
A faulty thermometer has its fixed points marked 5° and 95°. If the temperature of a body as shown on the Celsius scale is 40°C, then its temperature shown on this faulty thermometer is
A.
39°
B.
40°
C.
41°
D.
44°
Q15 Objective Physics Vol-2 1. Temperature MCQ
28 Jul 2026
Concept: Conversion between Celsius and Fahrenheit scales using a given ratio
The readings of a bath on Celsius and Fahrenheit thermometers are in the ratio 2 : 5. The temperature of the bath is
A.
-26.66°C
B.
40°C
C.
45.71°C
D.
26.66°C
Q16 Objective Physics Vol-2 1. Temperature MCQ
28 Jul 2026
Concept: Constant pressure gas thermometer and temperature calculation
The reading of air thermometer at 0°C and 100°C are 50 cm and 75 cm of mercury column, respectively. The temperature at which its reading is 80 cm of mercury column is
A.
105°C
B.
110°C
C.
115°C
D.
120°C
Q17 DPT 2. Thermal Expansion MCQ
28 Jul 2026
Concept: Thermal expansion in solids (Linear expansion)
A steel ruler exactly 20 cm long is graduated to give correct measurements at $20^\circ C$. What will be the actual length of the ruler when it is used in the desert at a temperature of $40^\circ C$? (Take $\alpha_{steel} = 1.2 \times 10^{-5} / ^\circ C$)
A.
$20.0024$ cm
B.
$20.0048$ cm
C.
$19.9952$ cm
D.
$20.048$ cm
Q18 DPT 2. Thermal Expansion MCQ
28 Jul 2026
Concept: Linear expansion and condition for constant difference in lengths
The length of a steel rod is 5 cm longer than that of a brass rod. If this difference in their lengths is to remain same at all temperatures, then find the length of the brass rod. (Coefficients of linear expansion for steel and brass are $12 \times 10^{-6} / ^\circ C$ and $18 \times 10^{-6} / ^\circ C$, respectively.)
A.
15 cm
B.
5 cm
C.
10 cm
D.
20 cm
Q19 DPT 2. Thermal Expansion MCQ
28 Jul 2026
Concept: Superficial (areal) expansion of solids
A metal ball having a diameter of 0.4 m is heated from 273K to 360 K. If the coefficient of areal expansion of the material of the ball is $0.000034 K^{-1}$, then determine the increase in surface area of the ball.
A.
$1.486 \times 10^{-3} m^2$
B.
$2.486 \times 10^{-3} m^2$
C.
$0.5024 \times 10^{-3} m^2$
D.
$3.486 \times 10^{-3} m^2$
Q20 DPT 2. Thermal Expansion MCQ
28 Jul 2026
Concept: Volume expansion and its relation to linear expansion
On heating a glass block of $10000 cm^3$ from $25^\circ C$ to $40^\circ C$, its volume increases by $4 cm^3$. Determine the coefficient of linear expansion of glass.
A.
$8.89 \times 10^{-6} / ^\circ C$
B.
$26.67 \times 10^{-6} / ^\circ C$
C.
$13.33 \times 10^{-6} / ^\circ C$
D.
$4.44 \times 10^{-6} / ^\circ C$
Q21 DPT 2. Thermal Expansion MCQ
28 Jul 2026
Concept: Volume expansion of liquids and its application in a thermometer
The volume of mercury in the bulb of a thermometer is $10^{-6} m^3$. The area of cross-section of the capillary tube is $2 \times 10^{-7} m^2$. If the temperature is raised by $100^\circ C$, then find the increase in the length of the mercury column. (Take $\gamma_{Hg} = 18 \times 10^{-5} / ^\circ C$)
A.
$4.5 cm$
B.
$9 cm$
C.
$18 cm$
D.
$0.9 cm$
Q22 DPT 2. Thermal Expansion MCQ
28 Jul 2026
Concept: When the temperature of a pendulum clock increases, its length increases, causing its time period to increase. The clock runs slow and loses time. The time lost or gained in a day is given by the formula $\Delta t = \frac{1}{2} \alpha \Delta \theta \times 86400$, where $\alpha$ is the coefficient of linear expansion, $\Delta \theta$ is the change in temperature, and 86400 is the number of seconds in a day.
A clock which keeps correct time at 20°C is subjected to 40°C. If the coefficient of linear expansion of the pendulum is $12 \times 10^{-6} /^\circ C$, determine the loss in time per day.
A.
10.4 s
B.
12.4 s
C.
8.2 s
D.
15.6 s
Q23 DPT 2. Thermal Expansion MCQ
28 Jul 2026
Concept: When the temperature of a pendulum clock increases, its length increases, causing its time period to increase. The clock runs slow and loses time. The change in time period is given by the formula $\Delta T = \frac{1}{2} \alpha \Delta \theta T$. The time lost or gained is given by the formula $\Delta t = \frac{\Delta T}{T'} \times t$, where $T'$ is the new time period and $t$ is the total time elapsed.
A second's pendulum clock has a steel wire. The clock is calibrated at $20^\circ C$. How much time does the clock loss or gain in one week when the temperature is increased to $30^\circ C$? (Take $\alpha_{steel} = 1.2 \times 10^{-5} /^\circ C$)
A.
42.15 s
B.
28.50 s
C.
36.28 s
D.
50.00 s