MCQ Chapter 9 General Science Class 7 Maharashtra Board MCQ For All Chapters – General Science Class 7Heat 1. What do you feel when you rub your palms together and place them on your cheeks?ColdnessWarmthNothingTinglingQuestion 1 of 202. Why does a halwai wrap cloth around the end of a slotted spoon while stirring boiling milk?To improve gripTo prevent heat conduction to the handTo clean the spoonTo increase heat transferQuestion 2 of 203. Why do we hold a steel glass with a handkerchief while drinking hot milk?To avoid slippingTo reduce heat transfer to the handTo absorb milkTo cool the milkQuestion 3 of 204. What happens when a hot object is near a cold one?Both stay the sameThe hot one gets hotterHeat transfers from hot to coldThe cold one gets colderQuestion 4 of 205. Which mode of heat transfer requires a solid medium?ConvectionRadiationConductionReflectionQuestion 5 of 206. In the metal bar experiment, why do pins fall first from the copper bar?Copper is heavierCopper conducts heat fasterCopper is colderCopper reflects heatQuestion 6 of 207. What is observed when potassium permanganate crystals are dropped into heated water?The water turns greenMagenta streams move up and downThe water remains clearCrystals sink without movementQuestion 7 of 208. Why does warm water move upwards in the convection experiment?It becomes denserIts density decreasesIt attracts cold waterIt contractsQuestion 8 of 209. Why doesn’t heat reach the ice at the bottom of the test tube when the top is heated?Conduction stopsConvection doesn’t occurRadiation is blockedIce reflects heatQuestion 9 of 2010. How does heat from a candle reach your hands without touching the flame?ConductionConvectionRadiationReflectionQuestion 10 of 2011. How does the sun’s heat reach the earth?Through conductionThrough convectionThrough radiationThrough air currentsQuestion 11 of 2012. What does an infrared camera use to make surroundings visible at night?Sound wavesHeat radiationVisible lightMagnetic fieldsQuestion 12 of 2013. Why is the water in the black-painted tin warmer after being in the sun?Black reflects heatBlack absorbs more heatBlack conducts heat lessBlack cools fasterQuestion 13 of 2014. Which object is a good conductor of heat in the hot water experiment?Plastic rulerPencilCopper stripWooden spoonQuestion 14 of 2015. Why can we hold a glass tumbler with hot tea more easily than a steel one?Glass is heavierGlass is a bad conductorSteel reflects heatGlass contractsQuestion 15 of 2016. Why do we wear woollen clothes in winter?They absorb heatThey are good conductorsThey are bad conductorsThey reflect coldQuestion 16 of 2017. What happens to a metal ball when heated in the ring experiment?It contractsIt expandsIt stays the sameIt meltsQuestion 17 of 2018. What happens to the metal ball after it cools down?It expands furtherIt contractsIt remains expandedIt cracksQuestion 18 of 2019. Why is there a gap at the joints of rails?To reduce frictionTo allow expansion in heatTo prevent contractionTo increase stabilityQuestion 19 of 2020. What happens to water’s volume when heated in the conical flask experiment?It decreasesIt increasesIt stays the sameIt evaporates completelyQuestion 20 of 20 Loading...
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