Heat: MCQ Test (50 questions)

Question 1 of 50

0°C on the Celsius scale is equal to how many degrees on the Fahrenheit scale?

A50°
B32°
C64°
D273°

Question 2 of 50

Which of the following liquids is a very good conductor of heat?

AMercury
BWater
CEther
Dbenzene

Question 3 of 50

Potatoes take more time to cook on mountain tops because-

AThe temperature at the top of the mountain is lower than the temperature at sea level.
BThe temperature is higher on the top of the mountain
Catmospheric pressure is high
Datmospheric pressure decreases

Question 4 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 5 of 50

Thermocouple is made by……….

Atwo nonmetals
Btwo similar metals
Ctwo dissimilar metals
Dnone of these

Question 6 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 7 of 50

Water is used to cool the radiator of an automobile because-

Awater has a high specific heat
Bthe density of water is low
CWater is cheap
DWater is available at low temperature.

Question 8 of 50

The normal body temperature of a human being is-

A98°F
B98°C
C68°F
D66°F

Question 9 of 50

In Adiabatic Change-

Aheat remains unchanged
Btemperature remains unchanged
CBoth heat and temperature change
Dnone of these

Question 10 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 11 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 12 of 50

Running a fan in hot weather gives relief because-

AThe fan gives cool air.
BOur sweat evaporates faster.
COur bodies radiate more heat
DThe conductivity of air increases.

Question 13 of 50

On which principle is the Thermo Couple Thermometer based?

AOn the Seebeck effect
BOn Joule's effect
COn the Peltier effect
Dnone of these

Question 14 of 50

The temperature of a liquid increases due to its vaporization.

Awill increase
Bwill decrease
Cwill grow rapidly
Dwill remain unchanged

Question 15 of 50

Water is used in hot water bags because-

AIt is easily available.
BIt is cheap and not harmful.
CIts specific heat is high
DIt is easy to heat water

Question 16 of 50

The presence of moisture in the atmosphere is ascertained by observing water droplets on the outer surface of a steel glass filled with-

Awith warm milk
Bwith hot water
Cwith cold water
Dfrom normal water

Question 17 of 50

If you touch an iron block and a wooden block in the morning during cold days, the iron block feels colder because-

AThe temperature of an iron block is lower than that of a wooden block
BIron is a better conductor of heat than wood
CIron is a poor conductor of heat compared to wood.
DIron block is heavier than wood

Question 18 of 50

The normal human body temperature is 98.4°F. Its equivalent temperature in °C is

A40.16
B36.891
C35.72
D32.36

Question 19 of 50

A body absorbs maximum heat when it is-

Ablack and rough
Bblack and smooth
Cwhite and rough
Dwhite and smooth

Question 20 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

Question 21 of 50

What does a white and smooth surface look like?

APoor absorber and poor reflector of heat
BGood absorber and good reflector of heat
Cpoor absorber and good reflector of heat
DGood absorber and poor reflector of heat

Question 22 of 50

Water is heated in an electric kettle by-

ACauses of conduction
Bdue to convection
Cdue to radiation
Dall of which

Question 23 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 24 of 50

When some water is continuously churned, its temperature increases. In this process-

AHeat energy is converted into thermal energy.
BThermal energy is converted into heat energy.
Cmechanical energy is converted into thermal energy
Dthermal energy is converted into mechanical energy

Question 25 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 26 of 50

Which of the following is the most appropriate colour combination for an umbrella to protect from the sun?

Ablack on top white on bottom
Bwhite on top black on bottom
CBlack top and bottom
DWhite top and bottom

Question 27 of 50

In winter, when water freezes due to cold, then fish and other aquatic creatures-

ACan survive because only the top layer of water freezes
Bmove to other warmer places
Ccan survive safely because they have an innate ability to tolerate cold
Ddies

Question 28 of 50

Cryogenic engines are used in-

AIn submarine propulsion
Bin frost-free refrigerators
Cin rocket technology
Din research on superconductivity

Question 29 of 50

The heat required to raise the temperature of a unit mass of a substance by one degree Celsius is-

Aspecific heat
Bheat capacity
Cwater equivalent
Dlatent heat

Question 30 of 50

The temperature at which ice, water and vapour remain in equilibrium is called—

AFreezing point
BBoiling point
Ccritical temperature
Dtriple point

Question 31 of 50

Newton's law of cooling is applicable only when-

AThe temperature difference should not be too great
BThe temperature difference is too great
Cdoes not depend on temperature difference
Dnone of these

Question 32 of 50

The inventor of Thermos Flask is-

ADivar
BStephen
CKirchhoff
DNewton

Question 33 of 50

The function of the thermostat in a refrigerator is-

ALowering the temperature
Bincrease freezing temperature
Cmaintaining a consistent temperature
DDecreasing the melting point

Question 34 of 50

The morning sun is not as hot as the afternoon sun because-

AThe sun's rays move slowly in the morning.
BThe sun is cold in the morning.
CThe Earth is farther from the Sun in the morning
DIn the morning, the sun's rays have to travel a greater distance in space.

Question 35 of 50

The inner walls of the Dharmas flask are shiny.

ATo prevent heat loss by convection
BTo prevent heat loss by radiation
CTo prevent heat loss by conduction
DNone of these

Question 36 of 50

When ice is heated from 0°C to 10°C, the volume of water-

Agrows uniformly
Bdecreases uniformly
Cfirst increases and then decreases
Dfirst decreases and then increases

Question 37 of 50

It is comfortable to wear white clothes in summer because-

AThey reflect all the heat falling on them.
BThey develop all the heat transferred from the body
CThey absorb sweat
DIt provides coolness to the eyes

Question 38 of 50

In which method of heat transfer do the molecules of the substance not move from one place to another on their own?

Aconduction
Bconvection
Cradiation
DAll three

Question 39 of 50

How much temperature can be measured by radiation pyrometer?

A100-250°C
BUp to 100°C
C250-500°C
DAbove 800°C

Question 40 of 50

The normal temperature of the human body in Kelvin is-

A280
B290
C300
D- 273°C

Question 41 of 50

The SI unit of temperature is-

AKelvin
BCelsius
Ccentigrade
DFahrenheit

Question 42 of 50

The heat required to convert a substance from liquid to gas without any change in temperature is called its latent heat?

AEvaporation
BUplift
Ccompaction
Devaporation

Question 43 of 50

The room can be cooled by-

Aby the flow of water
Bby releasing compressed gas
Cfrom cooking gas
Dby melting a solid

Question 44 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 45 of 50

An increase in the temperature of an object means that the object's-

Akinetic energy has increased
BThe potential energy has increased.
Cmechanical energy has increased
DThermal energy has increased.

Question 46 of 50

The concept of internal energy is derived from which law of thermodynamics?

Azero number rule
BFirst Law
CSecond Law
DThird Law

Question 47 of 50

Which temperature measured in Celsius is equal to 300 K?

A30°C
B27°C
C300°C
DNone of these

Question 48 of 50

Dew does not form on a windy night because-

AThe rate of evaporation is faster
BThere is less moisture in the air
CThe temperature remains high
DThe sky is not clear

Question 49 of 50

Why are white clothes cooler than black clothes?

Aabsorb all light that reaches them
BThey reflect whatever light reaches them.
Cdoes not allow light to penetrate
DCompletely cools the sunlight

Question 50 of 50

Which scientist first melted two pieces of ice by rubbing them together?

ARumford
BJoule
CDavy
DCelsius