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 L^{2} T^{-2}

(iii) M L^{-1} T^{-2}

(iv) M L^{-1} T^{-1}

Answer:

ML^{2} 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 × 10^{7} erg / calorie

(ii) 4.8 erg / calorie

(iii) 5.18 × 10^{7} erg / calorie

(iv) 5.18 erg / calorie

Answer:

4.18 × 10^{7} 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 × 10^{7}

(iii) \(\frac{1}{4.2}\)

Answer:

4.2 × 10^{7}

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 ML^{2} 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 × 10^{5}

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