Maharashtra Board Class 8 Science Solution Chapter 14 – Measurement and Effects of Heat
Balbharati Maharashtra Board Class 8 Science Solution Chapter 14: Measurement and Effects of Heat. Marathi or English Medium Students of Class 8 get here Measurement and Effects of Heat full Exercise Solution.
|Std||Maharashtra Class 8|
|Subject||General Science Solution|
|Chapter||Measurement and Effects of Heat|
(a.) Temperature of a healthy human body – 98.6 degree Fahrenheit.
(b.) Boiling point of water – 212 degree Fahrenheit.
(c.) Room temperature – 296 K
(d.) Freezing point of water – O degree Celsius.
(B) (a) F
(C) (a) Temperature
(b) Calori meter.
(2.) Nishigandha kept a vessel containing all the ingredients for making tea in a solar cooker. Shivani kept a similar vessel on a stove. Whose tea will be ready first and why?
Ans. Shivani tea will be prepared first. Because she was done in stove. Un case of stove the intensity of the flame in contact with the vessel is very high flame. As a result time taken by the tea to reach its boiling point will be less & it will quicker than solar heat. So Nishigandha’s tea will be take time more for made.
(3.) (a.) Describe a clinical thermometer. How does it differ from the thermometer used in laboratory?
Ans. Clinical thermometer:- A clinical thermometer is a thermometer used to measure human or animal body temperature. It is marked in degree centigrade or degree Fahrenheit. It run from 35 degree Celsius to 42 degree Celsius. It consist mercury which is accurate & sensitive, having narrow place where the mercury level rise very fast.
|Clinical Thermometer||Laboratory Thermometer|
|(i) It is used to measure body temperature.||(i) It is not used to measure body temperature.|
|(ii) Temperature range 35o C – 42o C||(ii) Temperature range -10o C to 110o C.|
(b.) What is the difference between heat and temperature? What are their units?
|(i) It described the transfers of thermal energy of molecules.||(i) It described the average kinetic energy of molecules.|
|(ii) Unit of heat are Joule, Calorie.||(ii) Unit of temperature are Celsius, Fehrenheit, Kelvin.|
|(iii) It is determined by an instruments.||(iii) It is determined by thermometer.|
|(iv) It is derived quantity.||(iv) It is fundamental quantity.|
SI unit – Joule.
CGS unit – Calorie.
Unit – Celsius, Fahrenheit, Kelvin.
(d.) Explain why rails have gaps at specific distances.
Ans. Rails are made iron metal. iron is super conductor of het. during heat molecules of iron metal are expended, as a result rails are also expended. After cooling it also remain their own shape. Due to this reason rain have gaps at specific distance for expending nature of iron to prevent accident.
(4) (a.) What must be the temperature in Fahrenheit so that it will be twice its value in Celsius?
(b.) A bridge is made from 20 m long iron rods. At temperature 18o C, the distance between two rods is 0.4 cm. Up to what temperature will the bridge be in good shape?
(c.) At 15o C the height of Eifel tower is 324 m. If it is made of iron, what will be the increase in length in cm, at 30o C?
(d.) Two substances A and B have specific heats c and 2 c respectively. If A and B are given Q and 4Q amounts of heat respectively, the change in their temperatures is the same. If the mass of A is m, what is the mass of B?
(e.) When a substance having mass 3 kg receives 600 cal of heat, its temperature increases by 10o C. What is the specific heat of the substance?