Heat: MCQ Test (50 questions)

Question 1 of 50

The water from the hand pump is hot in winter because-

AIn winter our body is cold, hence water appears warm.
BThe temperature inside the Earth is higher than the temperature in the atmosphere
CThe pumping action creates friction, which heats the water.
DWater from inside comes out and absorbs heat from the surroundings

Question 2 of 50

The temperature of the surface of the Sun is-

A600K
B2000K
C6000K
D7000K

Question 3 of 50

Thermos flask keeps liquids hot for a long time because-

AIt is filled with gas that emits heat.
BThere is internal heating in it.
CDouble walls of radiant inner wall and outer cladding prevent heat from escaping or entering
Dnone of the above

Question 4 of 50

If the boiling point of water in Delhi is 100°C, what will be the temperature of water in Mussoorie?

A100°C
Bless than 100°C
CMore than 100°C
DAll is false

Question 5 of 50

The method of transmission of heat is-

AConduction
BConvection
CRadiation
DAll of the above

Question 6 of 50

When two pieces of ice are pressed together, they stick together because-

AThe melting point of ice decreases due to increased pressure.
BDue to high pressure, the melting point of ice increases.
CDue to high pressure, the melting point of ice first decreases and then increases.
DThere is no relation between pressure and melting point.

Question 7 of 50

What effect does the addition of impurities have on the melting point?

Aincreases
Bdecreases
Cremains unchanged
Dnone of these

Question 8 of 50

Black skinned people from Africa compared to white skinned people from Britain-

Afeel more heat
Bfeel less heat
Cfeel the same heat
DDo not feel the heat

Question 9 of 50

The value of latent heat of fusion of ice is-

A0.8 Cal/g
B8 Cal/g
C80 Cal/g
D536Cal/g

Question 10 of 50

The temperature of boiling water at normal atmospheric pressure on the Fahrenheit scale is The temperature of boiling water at normal atmospheric pressure on the Fahrenheit scale is?

A32°F
B100°E
C180°F
D212°F

Question 11 of 50

Which thermometer measures the temperature of distant objects like the Sun etc.?

Aby thermocouple thermometer
BBy platinum resistance thermometer
Cby total radiation pyrometry
Dnone of these

Question 12 of 50

The temperature of an object on the Fahrenheit scale is 212°F. Its temperature on the Celsius scale would be

A- 32°C
B40°C
C100°C
D112°C

Question 13 of 50

The temperature of boiling water in a steam engine can be high due to what reason?

Asubstances dissolved in water
BThere is low pressure inside the boiler.
CThere is high pressure inside the boiler
DFire occurs at extremely high temperatures

Question 14 of 50

Food is cooked in less time in a pressure cooker because-

AThe temperature of boiling water decreases due to high pressure.
BIt is closed from all sides and hence does not have any effect on air.
CDue to high pressure the temperature of boiling water increases.
DEvaporation of the water used is very low.

Question 15 of 50

At what temperature is the density of water maximum?

Aat 0°C
Bat 4°C
Cat -4°C
Dat 100°C

Question 16 of 50

Mercury is generally used in thermometers because it has-

Ahave high liquidity
Bhas a high density
Chas high conductivity
DHas a high specific heat (SSC)

Question 17 of 50

If there is a sudden increase in the temperature of a place, then the relative humidity-

Aincreases
Bdecreases
Cremains stable
DIt keeps increasing and decreasing.

Question 18 of 50

On what does the rate of cooling depend?

Athe difference in temperature between the body and its surroundings
BRadiating surface area
CNature of the radiating surface
DAll of the above

Question 19 of 50

Why is ice packed in sawdust?

ASawdust doesn't stick to ice
BSawdust does not melt easily
CSawdust is a bad conductor of heat
DSawdust is a good conductor of heat

Question 20 of 50

Why does it snow on high hills?

ASome gas traps water vapor on high hills
BClouds are close to the earth on hills, so water vapor freezes and turns into ice.
COn high hills, the temperature is below freezing point, so water vapor freezes and turns into ice.
Dnone of the above

Question 21 of 50

When water is filled in a bottle and allowed to freeze, the bottle breaks because-

Awater expands when it freezes
BThe bottle contracts at freezing point.
CThe temperature outside the bottle is higher than inside.
Dwater expands when heated

Question 22 of 50

The rate of evaporation for a given liquid depends on-

Aat the temperature of the liquid
Bat air temperature
Cthe area of the open surface of the liquid
Don all the above factors

Question 23 of 50

On which principle is the Total Radiation Pyrometer based?

AOn the Seebeck effect
BOn the Peltier effect
COn Stefan's law
DOn Joule's effect

Question 24 of 50

Why can two thin shirts keep us warmer in winter than one thick shirt?

ATwo thin shirts become thicker, hence preventing the transfer of heat
BThe layer of air between the two shirts acts as a conductor.
CThe layer of air between the two shirts acts as a medium of insulation.
DThere is no radiation of heat

Question 25 of 50

Why is the outer bottom of cooking utensils left black?

AIt is difficult to clean it daily.
BBlack surface is a good conductor of heat
CBlack surface is a bad conductor of heat
DBlack surfaces are good heat absorbers

Question 26 of 50

The normal temperature of the human body in Kelvin is-

A280
B290
C300
D- 273°C

Question 27 of 50

The rate at which an object cools is directly proportional to the temperature difference between the object and the medium surrounding it. This law is:

ANewton's law of cooling
BStefan's radiation law
CKirchhoff's law
Dzero point law of thermodynamics

Question 28 of 50

Water pipelines in the mountains burst during extreme winter. This is because:

AThe pipe shrinks due to cold.
BWater in pipes shrinks when it freezes
CWater in pipes expands when it freezes
DPipes expand as they cool

Question 29 of 50

If water is cooled from 10°C to 0°C then-

AThe volume of water will decrease up to 4°C and then increase.
BThe density of water will continue to increase and reach a maximum at 4°C
CThe volume of water will continuously decrease and will reach its minimum at 4°C
DThe density of water will decrease up to 4°C and then increase.

Question 30 of 50

When does water boil?

AWhen its vapor pressure is one gram per square cm.
BWhen its vapour pressure is equal to 76 cm of mercury
CThe potential vapor pressure of water is equal to the atmospheric pressure.
DWhen the temperature of the water reaches 100°C

Question 31 of 50

Sweating cools the body because-

AThe presence of water on the skin provides coolness.
Blatent heat is required for vaporization
Cwater has a high specific heat
Dwater is a poor conductor of heat

Question 32 of 50

Why do metal teapots have wooden handles?

Awood is a poor conductor of heat
BIt does not consume electricity
CThis makes the character look beautiful
DIt is clean/

Question 33 of 50

Increasing the pressure on ice increases its melting point (mp)

Awill decrease
Bwill increase
Cwill remain unchanged
Dwill become zero

Question 34 of 50

When a table fan is run in a closed room, the air in the room-

Ait will be hot
Bit will be cold
Cwill have no effect
Dnone of the above

Question 35 of 50

The SI unit of temperature is-

AKelvin
BCelsius
Ccentigrade
DFahrenheit

Question 36 of 50

Clothes keep us warm in winter because-

Aprovide heat
BDoes not radiate heat.
CPrevents air from coming into contact with the body
DPrevents body heat from escaping

Question 37 of 50

Which of the following is correct?

A(F+32)/9=C/5
B(F-32)/9=C/5
C(C-5)/9=F/32
D(F-5)/9=C/32

Question 38 of 50

The reason why the snow covering the mountains does not melt all at once due to the heat of the sun is-

AIt becomes very hard
BIt reflects most of the heat received from the sun.
CIt has a low specific heat capacity
DIt has high latent heat of fusion

Question 39 of 50

Humans feel discomfort due to humidity. Which of the following is a suitable reason for this?

Aexcessive sweating
BReduced sweating
CSweat not evaporating due to humidity
Dnone of the above

Question 40 of 50

During winter, when the weather is of what type, we feel more cold?

Aclear weather
Bcloudy weather
Chumid weather
Ddry weather

Question 41 of 50

The Sun's heat reaches the Earth through which of the following types of transmission medium?

Aconvection
Bradiation
CSannayan
Dheat exchange

Question 42 of 50

Thermocouple is made by……….

Atwo nonmetals
Btwo similar metals
Ctwo dissimilar metals
Dnone of these

Question 43 of 50

If a metal is used to make cooking utensils, then the heat conductivity-

Ashould be less
BThere should be more
CElectrical conductivity should be low
DThe density should be high

Question 44 of 50

The radiation coming from the Sun is mainly in the form of?

Aonly light
BLight and long wavelength infrared radiation
Clight and short wavelength infrared radiation
DBoth short and long wavelength infrared radiation

Question 45 of 50

Very high temperatures are measured by-

Aplatinum resistance thermometer
Bfrom a thermocouple thermometer
Cfrom a total radiation pyrometer
Dnitrogen gas thermometer

Question 46 of 50

What is the process called when a liquid changes into its vapor before its boiling point?

Aevaporation
Bcompaction
Cfreezing
Dnone of these

Question 47 of 50

The change of state of matter from solid to liquid is called-

Amelting
BEvaporation
Cboiling
DNone of these

Question 48 of 50

The liquid in a thermos flask remains hot or cold for a long time because there is no loss or gain of heat.

AOperation
Bconvection and radiation
Cboth a and B
DNone of these

Question 49 of 50

By which method are the walls of a thermos flask coated to minimize heat transfer?

Aconduction
Bconvection
Cradiation
Dall of which

Question 50 of 50

The value of 1 kilocalorie of heat is-

A4.2 joules
B4.2 x 102 joules
C4.2 x 10 joules
D4.2 x 10 joules