Well structured WBBSE Class 9 Physical Science MCQ Questions Chapter 6 Heat can serve as a valuable review tool before exams.
Heat Class 9 WBBSE MCQ Questions
Multiple Choice Questions :
Question 1.
What is the unit of heat in SI system ?
(i) calorie
(ii) Joule
(iii) erg
(iv) Newton
Answer:
Joule
Question 2.
Who designed absolute scale of temperature ?
(i) Newton
(ii) Lord Kelvin
(iii) Celsius
(iv) Boyle
Answer:
Lord Kelvin
Question 3.
Which substance has the highest specific heat ?
(i) water
(ii) iron
(iii) gold
(iv) ice
Answer:
Water
Question 4.
The fundamental interval of celsius scale is divided into –
(i) 100
(ii) 180
(iii) 120
(iv) 102 division
Answer:
100
Question 5.
The fundamental interval of Fahrenheit scale is divided into
(i) 180
(ii) 100
(iii) 32
(iv) 212 division
Answer:
180
Question 6.
If C and F represent a particular temperature in Celsius and Fahrenheit scales respectively, then their relation is :
(i) \(\frac{C}{4}\) = \(\frac{F-32}{9}\)
(ii) \(\frac{C}{5}\) = \(\frac{F-32}{9}\)
(iii) \(\frac{C}{3}\) = \(\frac{F-32}{5}\)
(iv) \(\frac{C}{9}\) = \(\frac{F-32}{5}\)
Answer:
\(\frac{C}{5}\) = \(\frac{F-32}{9}\)
Question 7.
The temperature of a body is measured by the instrument :
(i) hydrometer
(ii) thermometer
(iii) voltameter
(iv) ammeter
Answer:
thermometer
Question 8.
How much calorie of heat would be produced by converting 42 joule of work completely into heat ?
(i) 100 calorie
(ii) 10 calorie
(iii) 1000 calorie
(iv) 90 calorie
Answer:
10 calorie
Question 9.
Normal body temperature of a man is –
(i) 98.4° C
(ii) 98.4° F
(iii) 98.4 K
(iv) 100° F
Answer:
98.4° F
Question 10.
Which substance has the highest specific heat?
(i) ethanol
(ii) water
(iii) acetone
(iv) ether
Answer:
water
Question 11.
If the specific heat of copper be 0.09, what will be the water equivalent of a block of copper of mass 50 g ?
(i) 45 g
(ii) 4.5 g
(iii) 450 g
(iv) 44 g
Answer:
4.5 g
Question 12.
What is the melting point of ice in Fahrenheit scale ?
(i) 0° F
(ii) 32° F
(iii) 180° F
(iv) 121° F
Answer:
32° F
Question 13.
What is the specific heat of water in SI system ?
(i) 4 2 joule
(ii) 4200 joule/kg
(iii) 4200 joule/kg/K
(iv) 42 erg
Answer:
4200 joule / kg / K
Question 14.
The dimension of heat is –
(i) M L T
(ii) M L2 T-2
(iii) M L-1 T-2
(iv) M L-1 T-1
Answer:
ML2 T-2
Question 15.
Generally body temperature of a man is measured in :
(i) Celsius scale
(ii) Fahrenheit Scale
(iii) Kelvin scale
(iv) none of these
Answer:
Fahrenheit
Question 16.
Heat reaches the earth from the sun by the process of –
(i) conduction
(ii) convection
(iii) radiation
(iv) expansion
Answer:
Radiation
Question 17.
The value of mechanical equivalent of heat in CGS system is :
(i) 4.18 × 107 erg / calorie
(ii) 4.8 erg / calorie
(iii) 5.18 × 107 erg / calorie
(iv) 5.18 erg / calorie
Answer:
4.18 × 107 erg / calorie
Question 18.
How much work is to be done to produce 50 calorie of heat ?
(i) 210 joule
(ii) 200 joule
(iii) 201 joule
(iv) 310 joule
Answer:
210 joule
Question 19.
The water equivalent of a body is equal to :
(i) mass of the body x specific heat
(ii) mass of the body / specific heat
(iii) mass of the body + specific heat
(iv) mass of the body – specific heat
Answer:
Mass of the body × specific heat
Question 20.
Mercury remains in liquid state for long range of temperature :
(i) -39° C to 357° C
(ii) -57° C to 457° C
(iii) -10° C to 257° C
(iv) -12° C to 122° C
Answer:
-39° C to 357° C
Question 21.
-40° C is equal to :
(i) -50° F
(ii) -40° F
(iii) -60° F
(iv) -80° F
Answer:
-40° F
Question 22.
1 Calorie is equal to –
(i) 4.18 Joule
(ii) 5.18 Joule
(iii) 3.18 Joule
(iv) 4.18 erg
Answer:
4-18 Joule.
Question 23.
If a temperature in Kelvin scale is TK and the temperature in Celsius scale is t° C, the relation is :
(i) TK = (273 + t°C)
(ii) TK = (273 – t°C)
(iii) TK = (273 / t°C)
(iv) none of these
Answer:
T K = (273 + t°C)
Question 24.
Calorimetry relates to the measurement of –
(i) heat
(ii) temperature
(iii) mechanical energy
(iv) none of these
Answer:
heat
Question 25.
Quantity of heat of a body depends on its –
(i) temperature
(ii) mass
(iii) material of the body
(iv) all of them
Answer:
all of them
Question 26.
Quantity of heat is given by –
(i) \(\frac{m s}{t}\)
(ii) mst
(iii) \(\frac{m t}{s}\)
(iv) \(\frac{m s t}{w}\)
Answer:
mst
Question 27.
Work done W and heat produced H are related to each other as(where J is the mechanical equivalent of heat)
(i) WH = J
(ii) H = JW
(iii) W = J H
(iv) W J H = 1
Answer:
W = JH
Question 28.
The value of mechanical equivalent of heat (in erg/calorie) is –
(i) 4.2 × 10-7
(ii) 4.2 × 107
(iii) \(\frac{1}{4.2}\)
Answer:
4.2 × 107
Question 29.
The latent heat of fusion of ice is –
(i) 80 cal g-1
(ii) 3.36 × 105 cal g-1
(iii) 80 joule kg-1
(iv) 3.36 cal g-1
Answer:
80 cal g-1
Question 30.
Saturated vapours obeys –
(i) Boyle’s law
(ii) Charles’ law
(iii) pressure law
(iv) none of these
Answer:
none of these
Question 31.
Dews are formed at a temperature –
(i) greater than dew point
(ii) less than dew point
(iii) equal to dew point
(iv) at critical temperature.
Answer:
equal to dew point
Question 32.
The volume of water is minimum at a temperature –
(i) -4°C
(ii) 4°C
(iii) 0°C
(iv) 1°C
Answer:
4°C
Question 33.
Thermal capacity of a body of mass m and specific heat s is –
(i) \(\frac{\mathrm{m}}{\mathrm{s}}\)
(ii) \(\frac{\mathrm{m}}{\mathrm{s}}\)
(iii) \(\frac{\mathrm{m}}{\mathrm{s}}\)
(iv) ms
Answer:
ms
Fill in the blanks :
1. Heat is the cause and temperature is the _____.
Answer:
effect
2. Heat is a form of _____ a body possesses.
Answer:
energy
3. The range of temperature between the upper and lower fixed point is known as _____ interval.
Answer:
fundamental
4. Kelvin scale of temperature starts from the temperature corresponding to _____, taken as zero Kelvin.
Answer:
-273° C
5. Mean calorie is _____ of the heat necessary to raise the temperature of 1 gram pure water from 0° C} to 100° C.
Answer:
(\(\frac{1}{100}\)) th
6. 1 calorie = 4.18 or approximately 4.2 _____.
Answer:
joule
7. Specific heat of _____ in SI system is 4200 J/kg/K.
Answer:
water
8. Thermal capacity or heat capacity of a body is defined as the ratio of the heat supplied to a body to its consequent rise in _____.
Answer:
temperature.
9. In _____ process heat is transmitted in wave form.
Answer:
radiation
10. In radiation process _____ is not required.
Answer:
medium
11. Heat reaches the earth from the sun by _____ process.
Answer:
radiation
12. Normal body temperature of a man is _____ degree celsius.
Answer:
36.9
13. 94° F = _____ °C.
Answer:
34.4
14. The water equivalent of a body is = mass x _____.
Answer:
specific heat
15. A body becomes hot by _____ heat and becomes cold on giving away heat.
Answer:
taking
16. Temperature is the condition of a body.
Answer:
thermal
17. Melting point of _____ under normal atmospheric pressure is taken as the lower fixed point of a scale of temperature.
Answer:
ice
18. The quantity of heat required to raise the _____ of unit mass of a substance through one degree is called the specific heat of the substance.
Answer:
temperature
19. When work is completely converted into heat or heat is compietely converted into work, one is _____ to the other.
Answer:
equivalent
20. Work done to produce unit heat is known as _____ equivalent of heat.
Answer:
mechanical
21. Heat is a _____ quantity.
Answer:
scalar
22. In CGS system the unit of specific heat is _____
Answer:
Calorie/g/°C
23. The unit of specific heat in SI system is _____
Answer:
J/kg/K
24. -40°C = _____ °F
Answer:
-40
25. What is the dimension of heat ?
Answer:
The dimension of heat is ML2 T-2.
26. 1°C = ______ °F
Answer:
\(\frac{9}{5}\)
27. in CGS system heat is measured by the unit called _____.
Answer:
Calorie
28. Temperature of a body depends on the _____ contained in it.
Answer:
heat
29. In SI system the unit of thermal capacity is _____.
Answer:
JK-1
30. 1 kcal = _____ cal
Answer:
1000
31. In case of change of state, heat is _____ or liberated.
Answer:
absorbed
32. Latent heat of fusion of ice is _____ Jkg-1
Answer:
3.36 × 105
33. Specific heat of _____ is highest than any other common substance.
Answer:
Water
34. The temperature at which dews are formed called _____point.
Answer:
dew
35. The density of water at 4°C is _____.
Answer:
maximum
36. In CGS system, latent heat of vapourization of water is _____.
Answer:
540 cal/g/°C