Well structured WBBSE Class 10 Physical Science MCQ Questions Chapter 4 Thermal Phenomena can serve as a valuable review tool before exams.
Thermal Phenomena Class 10 WBBSE MCQ Questions
Multiple choice questions (MCQ) :
Question 1
The Fahrenheit and kelvin scales of temperature will the same reading at
(A) -40
(B) 313
(C) 574.25
(D) 732.25
Answer:
(B) 5 ?
Question 2
At what temperature, volume of an ideal gas at 0°C becomes triple?
(A) 182°C
(B) 819°C
(C) 546°C
(D) 646°C
Answer:
(C) 546°C
Question 3.
The specific heat of ice at 0°C melting into at 0°C is:
(A) zero
(B) infinity
C) more than zero
(D) less than zero
Answer:
(B) infinity
Question 4.
Boiling water is changing into steam. The specific heat of boiling water is:
(A) Zero
(B) One
(C) infinity
(D) less than one
Answer:
(C) infinity
Question 5.
Which of the following has the highest specific heat?
(A) copper
(B) water
(C) hydrogen
(D) silver
Answer:
(C) hydrogen
Question 6.
One gram of ice at 0°C is added at 5 g of water to 10°C. Final temperature of the mixture is:
(A) -5°C
(B) 5°C
(C) 0°C
(D) none of these
Answer:
(A) -5°C
Question 7.
The specific heat of an ideal gas varies with temperature T as :
(A) T1
(B) T2
(C) T-1
(D) T0
Answer:
(D) T0
Question 8.
22 g CO2 at 27°C is mixed with 16 g of oxygen at 37°C. The temperature of the mixture is :
(A) 32°C
(B) 27°C
(C) 37°C
(D) 30°C
Answer:
(A) 32°C
Question 9.
A ballon contains 500 m3 of He at 27°C and 1 atmospheric pressure. The volume of He at -3°C and 0.5 atmospheric pressure will be:
(A) 700 m3
(B) 900 m3
(C) 1000 m3
(D) 500 m3
Answer:
(B) 900 m3
Question 10.
The specific heat of a gas in a gas in an isothermal process is:
(A) infinite
(B) zero
(C) negative
(D) remains constant
Answer:
(A) infinite
Question 11.
100 g of ice is mixed with 100 g of water at 100°C. The final temperature of the mixture is:
(A) 10°C
(B) 20°C
(C) 40°C
(D) 30°C
Answer:
(A) 10°C
Question 12.
Heat given to a body which rises its temperature by 1°C is:
A water equivalent
(B) specific heat
(C) thermal capacity
(D) temperature gradient
Answer:
(C) thermal capacity
Question 13.
During the adiabatic process, the pressure of a gas is found to be proportional to the cube of its absolute temperature.
The ratio \(\fracC_p}C_v}\) for gas is :
(A) \(\frac{4}3}\)
(B) 2
(C) \(\frac{5}3}\)
(D) \(\frac{3}2}\)
Answer:
(D)
Question 14.
A gaseous mixture consists of 16 g of Helium and 16 g Oxygen. The ratio \(\fracC_p}C_v}\) of the mixture is :
(A) 1.54
(B) 1.4
(C) 1.63
(D) 1.59
Answer:
(C) 1.63
Question 15
Two bars of copper having same length but unequal cross-section are heated to the same temperature. The change in length will be:
(A) equal in both bars
(B) more in thicker bar
(C) more in thinner bar
(D) cannot say
Answer:
(A) equal in both bars
Question 16
A body cools from 60°C to 50°C in 10 min. If room temperature be 25°C, temperature of the body at the end of next 10 min will be:
(A) 38.5°C
(B) 40°C
(C) 45°C
(D) 42.85°C
Answer:
(D) 42.85°C
Question 17
A body takes T minutes is cool from 62°C to 61°C when the surrounding temperature is 30°C. The time taken by the body to cool is 30°C. The time taken by the body to cool 46°C to 45°C is
(A) greater than T minute
(B) equal to T minute
(C) less than T minute
(D) equal to T/2
Answer:
(A) greater than T minute
Question 18
If the temperature of a block body is doubled, the wavelength at which the spectral radiancy has its maximum is :
(A) doubled
(B) halved
(C) quadrupled
(D) unchanged
Answer:
(B) halved
Question 19
A black body has maximum wavelength 1 m at 2000 K. Its corresponding wavelength at 3000 K will be :
(A) \(\frac{3}{2}\) λ m
(B) \(\frac{2}{3}\) λ m
(C) \(\frac{16}{81}\) λ m
(D) \(\frac{81}{16}\) λ m
Answer:
(B) \(\frac{2}{3}\) λ m
Question 20.
A body cools from 50°C to 40°C in 5 minutes. Its temperature comes down to 33.33°C in next 5 minutes. The temperature of surrounding is:
(A) 15°C
(B) 20°C
(C) 25°C
(D) 10°C
Answer:
(B) 20°C
Question 21
The rate of cooling at 600 K, if surrounding temperature is 300 K is R. The rate of cooling at 900 K is :
(A) \(\frac{16}{3}\) R
(B) 2 R
(C) 3 R
(D) \(\frac{2}{3}\) R
Answer:
(A) \(\frac{16}{3}\) R
Question 22
If Im denotes the wavelength at which the radiative emission from a black body at a temperature TK is maximum, then
(A) λm ∝ T
(B) λm ∝ T-1
(C) λm ∝ T2
(D) λm does not depend on T.
Answer:
(B) λm ∝ T-1
Question 23
Two spheres made of same material have radii in the ratio 1 : 2. Both are at same temperature. Ratio of heat radiation energy emitted per second by them is:
(A) 1 : 2
(B) 1 : 4
(C) 1 : 8
(D) 1 : 16
Answer:
(B) 1 : 4
Question 24.
The coefficient of linear expansion of a solid is :
(A) 3 γ
(B) 2 γ
(C) γ
(D) γ / 3
Answer:
(D) γ / 3
Question 25.
A good insulator of heat is
(A) Copper
(B) Mercury
(C) trapped air
(D) Iron
Answer:
(C) tropped air
Question 26.
A bimetallic strip bends on heating due to :
(A) Uneven expansions
(B) Same expansion
(C) No expansions
(D) None of these
Answer:
(A) Uneven expansions
Question 27.
The coefficient of linear expansion of a solid depends on :
(A) unit of length
(B) scale of temperature
(C) density of the material
(D) None of these
Answer:
(B) scale of temperature
Question 28.
A bimetallic strip bends upon heating because of
(A) same expansion
(B) uneven expansion
(C) no expansion
(D) twisting
Answer:
(B) uneven expansion
Question 29.
If the value of coefficient of linear expansion is 1.5 × 10-4 ° C-1 then value of coefficient of superficial expansion is :
(A) 4.5 × 10-4 °C-1
(B) 3.0 × 10-4 ° C-1
(C) 6.0 × 10-4 ° C-1
(D) 7.5 × 10-4 ° C-1
Answer:
(B) 3.0 × 10-4 ° C-1
Question 30.
When a solid metallic sphere is heated, the largest percentage increase occurs in its.
(A) Diameter
(B) Surface area
(C) Volume
(D) Density
Answer:
(C) Volume
Question 31.
For a liquid, the coefficient of apparent expansion (δa) and coefficient of real expansion (γ) are related as :
(A) δa = γr
(B) γa > γru
(C) γa < γr
(D) γa / γr = constant
Answer:
(C) γa < γr
Question 32.
Coefficient of linear expansion of the following metals are in the order
(A) aluminium < copper < iron
(B) copper < iron < aluminium
(C) copper < aluminium < iron
(D) aluminium > copper > iron
Answer:
(D) aluminium > copper > iron
Question 33.
The thermal conductivity of a rod is 2. what is its resistivity?
(A) 0.5
(B) 1
(C) 0.25
(D) 2
Answer:
(A) 0.5
Question 34.
Thermal conductivity of which of the following is the maximum?
(A) copper
(B) silver
(C) diamond
(D) platinum
Answer:
(C) diamond
Question 35.
The magnitude of thermal conductivity of the following substances are in the order.
(A) silver > aluminium > glass > wood
(B) aluminium > silver > glass > wood
(C) silver > aluminium > wood > glass
(D) aluminium > silver > wood > glass
Answer:
(A) silver > aluminium > glass > wood
Question 36.
A liquid which is a good conductor of heat is :
(A) kerosin
(B) mercury
(C) water
(D) turpentine
Answer:
(B) mercury
Question 37.
For an ideal heat insulator, value of K is :
(A) zero
(B) 1
(C) 100
(D) α
Answer:
(A) zero
Fill in the blanks :
1. Heat is a form of _________.
Answer:
energy.
2. Three different types of motions are translational motion, vibrational motion and ___________.
Answer:
Rotational motion.
3. SI unit of heat is __________.
Answer:
Joule.
4. 1 calorie = __________ Jule.
Answer:
4.18
5. Temperatures are measured with a __________.
Answer:
thermometer.
6. ______ is the upper fixed point in Fahrenheit scale.
Answer:
212° F
7. Three types of expansions in solids are, linear expansion, superficial expansion and __________.
Answer:
volume expansion.
8. Real expansion of the liquid = expansion of the vessel + __________.
Answer:
apparent expansion of the liquid.
9. γs = γn + ________.
Answer:
γ8
10. The volume of water is minimum at ______.
Answer:
4°C
11. The density of water is maximum at ______.
Answer:
4°C.
12. From Charle’s Law, we find γp = ______ °C-1.
Answer:
\(\frac{1}{273}\)
13. From pressure law, we find γy= ________ °C-1.
Answer:
\(\frac{1}{273}\)
14. Specific heat of water in SI system is ________.
Answer:
4200 Jkg-1 K-1.
15. The unit of thermal conductivity in SI system is ________.
Answer:
Jm-1 s-1 K-1.
16. The unit of thermal conductivity in CGS system is ________.
Answer:
cm2 s-1
17. Carbon dioxide is a ________ gas.
Answer:
green house.
18. The expansion of a substance on heating is called ________ expansion.
Answer:
thermal.
19. The coefficient of linear expansion of a solid does not depend on unit of ________.
Answer:
length.
20. Thermal resistivity is the _______ of thermal conductivity.
Answer:
reciprocal.
21. In charles’ law, a _______ mass of gas is taken.
Answer:
given.
22. A liquid good conductor of heat is ________.
Answer:
mercury.
23. In summer the pendulum clock becomes ________.
Answer:
slower
24. The unit of γ (i.e, coefficlent of cubical expansion) in S.I unit is ________.
Answer:
K-1
25. Material of the rod remaining same, longer the rod, ________ will be the increase in length of the rod for same increase in temperature.
Answer:
more.
26. If the value of α is 24 × 10-6 °C-1, then its value in S.I. unit is ________.
Answer:
24 × 10-6 K-1
27. Unit of β (coefficient of superficial expansion) is ________.
Answer:
°C-1 or K-1
28. For a particular solid substance, magnitude of β has the value of α [symbols have their usual meaning].
Answer:
twice
29. For two rods of same length and same area of cross-section, if temperature is raised by same amount, iron rod will expand ______ compared to that of the aluminium rod.
Answer:
less
30. The reciprocal of thermal conductivity is known as ________.
Answer:
thermal resistivity.
31. The S.I unit of thermal conductivity is ________.
Answer:
jm-1.k-1.s-1
32. Diamond has ________ value of K (i.e., coefficient of thermal conduction) than copper.
Answer:
higher
33. Brass is a ________ conductor of heat.
Answer:
good
34. In solids, heat passes from hotter region to colder region by ________ processes.
Answer:
conduction
State whether the following statement is True or False : VSA
1. In winter the pendulum clock becomes slower.
Answer:
False
2. β (i.e. coefficient of superficial expansion) is the characteristic of the material.
Answer:
True
3. For an ideal gas, (δ i.e., coefficient of cubical expansion) = 1 / 273
Answer:
True
4. α, β and δ are related as follows α : β : δ = 1 : 2 : 3
[Symbols have their usual meaning]
Answer:
True
5. Real expansion of the liquid = Apparent expansion of the liquid+volume expansion of the container.
Answer:
True
6. The seasonal changes in a pendulum clock are due to the expansion or contraction of solid substances.
Answer:
True
7. The S.I. unit of thermal conductivity is jm-2 ks-1
Answer:
False
8. Usually metals are good conductors of heat than gases and nonmetals.
Answer:
True
9. Diamond has low value of K (i.e. coefficient of thermal conduction)
Answer:
False
10. In solids, heat passes from hotter region to colder region by convection processes.
Answer:
False
11. A substance with a large thermal conductivity is a good conductor while the one with a small thermal conductivity is a poor heat conductor.
Answer:
True