The following 20 Multiple Choice Questions (MCQ) are based on
Chapter 7: Heat Transfer in Nature from the NCERT Class 7
Science textbook Curiosity. Each question has four options - select the
best answer and click to check.
Instructions: Read each question carefully. Choose the most
appropriate option from (a), (b), (c), or (d). Click
Show Answer to reveal the correct answer with explanation.
Multiple Choice Questions
1Heat naturally flows from:
(a) A hotter body to a colder body
(b) A colder body to a hotter body without work
(c) Both directions equally
(d) A body with less mass to more mass
(a) is correct
Heat transfer continues from higher to lower temperature until thermal equilibrium is approached.
2Conduction is heat transfer mainly through:
(a) Bulk movement of a fluid
(b) Empty space only
(c) Evaporation alone
(d) Direct particle-to-particle interaction
(d) is correct
Energy passes through a material without bulk movement of the material.
3Which material is a good conductor of heat?
(a) Plastic
(b) Wool
(c) Copper
(d) Wood
(c) is correct
Metals such as copper transfer heat efficiently.
4Why are cooking pan handles often made of wood or plastic?
(a) They produce convection
(b) They are poor conductors of heat
(c) They conduct heat faster than metal
(d) They increase flame temperature
(b) is correct
Insulating handles reduce heat reaching the user's hand.
5In a heated metal strip with wax-fixed pins, which pin falls first?
(a) The pin nearest the heated end
(b) The farthest pin
(c) All pins before heating
(d) No pin can fall
(a) is correct
Heat reaches nearby wax first, causing it to melt.
6Convection occurs mainly in:
(a) Solids only
(b) A perfect vacuum
(c) Metals only
(d) Liquids and gases
(d) is correct
Fluid particles can move in bulk and carry thermal energy.
7When water is heated from below, warmer water rises because it becomes:
(a) Solid
(b) Heavier per unit volume
(c) Less dense
(d) More dense
(c) is correct
Heating expands water, lowering its density relative to cooler water.
8The continuous movement of warm and cool fluid is called a:
(a) Chemical reaction
(b) Convection current
(c) Light ray
(d) Electric circuit
(b) is correct
Rising warm fluid and sinking cool fluid establish circulation.
9During daytime, a sea breeze usually blows:
(a) From sea to land
(b) From land to sea
(c) Only upward
(d) From mountains to valleys
(a) is correct
Land heats faster, so rising air over land is replaced by cooler air from the sea.
10At night, a land breeze usually blows:
(a) From sea to land
(b) Only from south to north
(c) Straight downward
(d) From land to sea
(d) is correct
Land cools faster, making air pressure relatively higher over land.
11Radiation transfers heat through:
(a) Only moving water
(b) Material particles alone
(c) Electromagnetic waves without needing a medium
(d) Only direct contact
(c) is correct
Radiant energy can cross empty space, as sunlight does.
12Heat from the Sun reaches Earth mainly by:
(a) Evaporation
(b) Radiation
(c) Conduction
(d) Convection through space
(b) is correct
Space between Sun and Earth lacks a material medium for conduction or convection.
13Which surface absorbs radiant heat most effectively?
(a) A dull black surface
(b) A shiny white surface
(c) A polished mirror
(d) A reflective silver surface
(a) is correct
Dark, dull surfaces are generally good absorbers and emitters of radiation.
14Why are light-coloured clothes preferred in hot weather?
(a) They absorb all radiation
(b) They stop convection entirely
(c) They generate cold
(d) They reflect more solar radiation
(d) is correct
Greater reflection reduces radiant heat absorbed by the body.
15Evaporation in the water cycle is driven mainly by:
(a) Soil pressure
(b) Magnetism
(c) Solar heat
(d) Moonlight only
(c) is correct
The Sun supplies energy for liquid water to enter the atmosphere as vapour.
16Condensation changes water vapour into:
(a) Sunlight
(b) Liquid droplets
(c) Hydrogen gas
(d) Solid rock
(b) is correct
Cooling vapour forms tiny droplets that can build clouds.
17Water returning from clouds as rain or snow is called:
(a) Precipitation
(b) Evaporation
(c) Transpiration
(d) Conduction
(a) is correct
Precipitation transfers atmospheric water back to Earth's surface.
18Water entering soil and moving downward is called:
(a) Radiation
(b) Condensation
(c) Combustion
(d) Infiltration or seepage
(d) is correct
Part of rainfall penetrates soil and can recharge groundwater.
19Groundwater is commonly stored in permeable layers called:
(a) Convection cells
(b) Clouds
(c) Aquifers
(d) Atmospheres
(c) is correct
Aquifers are water-bearing rock or sediment layers.
20Which action helps recharge groundwater?
(a) Removing vegetation everywhere
(b) Allowing rainwater to infiltrate soil
(c) Paving every open surface
(d) Pumping without limit
(b) is correct
Rainwater harvesting and permeable ground increase seepage into aquifers.
